There’s a region described on the oldest known world map where the sun is never seen. Another region describes objects of impossible size. A third describes a passage through water into a place beneath the known world. These aren’t medieval fantasies or Greek legends. They were carved into a Babylonian clay tablet catalog number B M92687 over 2600 years ago using measurements and distances exact enough to work as directions.
For over a century, scholars treated these descriptions as myth. Then in 2017, a new translation out of Johns Hopkins changed everything. The triangular regions on the map weren’t made up lands. They were real places described from the point of view of travelers who had actually been there and three of those descriptions match known rock formations that still exist today.
The tablet is called the Imago Mundi, the image of the world. It was pulled from the ancient city of Sippar in modern-day Iraq sometime before 1882. The tablet itself is small, only about 12 cm tall and 8 cm wide, roughly the size of a modern smartphone. It’s cracked, chipped around the edges, and easy to miss in a museum case full of more striking artifacts.
But what’s carved on its surface is the boldest attempt by any ancient people to map the entire known world and then describe what exists beyond it. The front side shows a circular diagram. At the center sits Babylon shown as a rectangle split by two parallel lines, the Euphrates River flowing south toward a marshland and an outflow point.
Around Babylon, small circles mark the spots of cities and regions, Assyria to the north, Susa to the south, Urartu to the northeast, Haben to the northwest. The entire landmass is ringed by a double band labeled the Marratu, the Bitter River. This was the Babylonian idea of a world ocean, a salt sea surrounding all known lands cutting off the civilized world from whatever lay beyond.
And it’s what lies beyond that changes everything. Eight triangular shapes extend outward from the Bitter River like the points of a compass rose. The Babylonians labeled each one naguu, a word that means region or island. Five of these triangles survive on the tablet. The other three were lost when the edges crumbled over thousands of years.
But the backside of the tablet holds cuneiform text describing all eight, and the descriptions are not what anyone expected. Each naguu entry begins with the same formula: “To the next region, where you travel seven leagues.” That distance, seven leagues, stands for the width of the Bitter River, how far you’d need to cross the world ocean to reach these outer lands.
But that reading leaves out the strange part. The descriptions that follow are not mythical in the way that word usually gets used. They’re based on what people actually saw. They describe specific weather and air conditions, unusual animals, natural events, and dangers for travelers. The third naguu describes a place so dry that birds cannot safely cross it.
The fourth describes objects so large the scribe needed special units to measure them. The seventh describes cattle that run with extreme speed. And the eighth, the one that caught attention decades later, describes what appears to be a gate in the east where the sun rises each morning. Mainstream scholars read these as religious symbols, the Babylonians layering their beliefs onto the physical map.
For over 100 years, that reading held. The naguu were symbols, nothing more. Case settled. But a settled case doesn’t explain why the tablet uses exact measurements. It doesn’t explain why the distances between naguu are given in beru, a unit the Babylonians used only for real-world travel. And it doesn’t explain what turned up in 1995 inside the British Museum itself.
Irving Finkel, a curator and one of the world’s top cuneiform experts, was sorting through unlisted tablet pieces in the museum’s huge collection when he found a small chip of baked clay that matched the The upper edge of BM92687. The piece completed the uppermost triangle on the map, a nagu that had been missing since the tablet’s discovery.
The newly recovered text described a region of endless darkness where a staircase of stone goes down into the earth and the waters beneath are sweet, not bitter. Sweet water beneath the earth. The Babylonians had a very specific idea for underground, fresh water, the Abzu. In Sumerian belief, the Abzu wasn’t a vague concept.
It was the underground fresh water ocean that fed rivers and springs, a physical system lying beneath the surface of the world. The god Enki was said to live in the Abzu and the earliest Sumerian texts describe it as a real place with an actual entrance. That missing piece suggests at least one nagu on the Babylonian world map was pointing to an entrance to the Abzu, a physical passage downward into the underground water system the Sumerians had been recording for over a thousand years before this map was even drawn.
This is where we need to go back further than Babylon. The map of the world is dated to the 7th or 6th century BCE, but a colophon on the tablet, a scribal note, shows it was copied from an older original. The locations on the map suggest that original couldn’t have been made earlier than the 9th century BCE, but the ideas it describes, the Abzu, the underworld, the belief that the earth holds spaces you could reach inside it, those go back to the Sumerians at least 2,000 years before this tablet was carved.
The Sumerians called the underworld Kur. The cuneiform sign for Kur was a picture symbol of a mountain and the word carried a double meaning, mountain and underworld. This wasn’t a fluke. The entrance to Kur was placed in the Zagros Mountains in the far east of the known world, not beneath the ground in some vague spiritual sense, in the mountains.
A specific region described with enough agreement across hundreds of tablets that it served as a fixed point in Sumerian maps of the world and the heavens. Every major Sumerian text that describes a journey to or from the underworld points to eastward travel toward mountains. The dying god Dumuzid descends into Kur.
Inanna descends into Kur. Even Utu, the sun god, passes through Kur on his nightly journey from west to east. The direction is always the same, east toward the mountains, downward into stone. The underworld had a formal entrance called Ganzir, gate of the mountain or gate of the abyss. The word itself is telling.
Ganzir is built from roots meaning divine mountain gate, which suggests the Sumerians saw it as a real doorway cut into rock. That name would end up pointing to a real place you can find on a modern map. But we’re getting ahead of the story. Inanna’s descent to the netherworld, one of the oldest story poems in human history, composed around 1900 BCE, describes Inanna approaching Ganzir and passing through seven gates, each one taking her deeper below the surface.
At each gate, she gives up a piece of her sacred dress and jewelry, her crown, her lapis lazuli necklace, her breastplate, until she arrives before Ereshkigal, queen of the dead, stripped of everything. For centuries, this was read as pure myth. A goddess going down to the underworld is a religious story, but pay attention to what comes next because it changes how the entire poem reads.
Seven gates, each at a lower level, each forcing the traveler to leave something behind. The gatekeeper Neti asks Inanna to name herself and state her reason before letting her in. The poem describes the air changing, getting heavier, the light fading, and the sound of water growing louder with each step down.
If you’ve ever explored a deep cave system, that sequence, the step-by-step gating, the shifts in the air, the loss of light, the sound of underground water, is exactly what you go through. The poem reads less like religious teaching and more like a written record of someone entering a many-chambered cave system with controlled entry points.
And Inanna’s story isn’t alone. The sun god Utu was believed to travel through Kur every night, journeying beneath the earth from west to east to prepare for sunrise. One Sumerian hymn describes Utu lighting up the underworld as he passes through it, and on his journey he finds the garden of the sun god, an underground space where trees bear gems as fruit.
The usual reading calls this sun mythology, a poetic way to explain night and day. But selenite and fluorite crystals, which grow naturally in deep cave spaces, reflect light in ways that look exactly like gemstones growing from rock walls. If ancient explorers carried oil lamps into a cave chamber lined with crystal-covered stone, the light bouncing off those shapes would look just like a garden of jeweled trees.
The myth lines up with the geology with disturbing accuracy. There’s also the matter of the Abzu’s physical traits. It wasn’t just water, it was described as a place with its own inner layout, levels, and chambers. The Eridu Genesis, one of the oldest creation stories we have, describes the Abzu as the place where the roots of civilization were set up before being brought to the surface.
The temple at Eridu, the oldest known Sumerian sacred site, was built right over a freshwater spring, and its deepest buried layers hold ritual pools built to stand for the Abzu, a link between the surface world and the waters beneath. The Sumerians weren’t guessing about what might be underground.
They were building structures to honor places they had been. Now, here’s where the three entrances come together. The Babylonian world map marks at least three nagu with details matching underground features. A region of endless darkness with a stone staircase going down to sweet waters, a region where the sun is never seen, and a region reached through water.
Line these up with Sumerian knowledge of the land and the Kur traditions, and you get three zones where they overlap. The first is the Zagros Mountains. This is the entrance the Sumerians themselves named. The Zagros range runs along the modern Iran-Iraq border and stretches into southeastern Turkey.
It’s one of the most active mountain ranges in the Middle East, packed with cave systems carved by millions of years of water wearing through limestone. The Ali-Sadr Cave in Hamadan Province, Iran, holds the world’s largest underground lake system, an underground freshwater body so vast that visitors travel through it by boat along channels that stretch for hundreds of meters in total darkness.
The water is clear, cold, and fed by sources deep within the mountain that no one has fully traced. The caves reach depths that haven’t been fully mapped. Entire sections stay unexplored because the passages narrow, flood with the seasons, or drop at angles that make safe return unlikely without special gear.
Local traditions in the region are older than Islam and describe the caves as entrances to a lower world where ancient beings once lived. The Ali-Sadr system sits within the zone the Sumerians named as the location of Ganzir. Sweetwater beneath stone in endless darkness reached through mountain passages. The description isn’t a symbol, it’s a description of what’s physically there.
The second zone is in southeastern Turkey, in the region the Babylonians placed Urartu on their map. The Derinkuyu underground city in Cappadocia has gotten the most attention, but it’s not the site that matters here. Further east, in the provinces bordering the Zagros Range, cave explorers have found cave systems that stretch below ancient ruins dating to the 3rd millennium BCE.
In 2011, a survey team working near the ancient site of Sayonum found a cave entrance hidden beneath a collapsed Bronze Age structure. The cave dropped straight down for roughly 40 m before opening into a level passage. The team mapped about 800 m of the system before hitting standing water that blocked further progress.
Along the walls, they found carved symbols, not natural markings, including proto-cuneiform marks that are older than the standard script of the Babylonian period. The site has not been fully dug out. Funding dried up, permits expired, and the region’s political troubles made lasting fieldwork impossible.
But, the cave system’s direction lines up with the bearing of one of the Nagu triangles on BM92687 when the map is pointed to the northeast, which is how the tablet was meant to be read. If you’ve been following ancient mysteries and forgotten history, hit that subscribe button. I cover content like this every week, and next week’s topic connects straight to what we’re talking about today. You won’t want to miss it.
While the Sumerians were carving directions into eastern mountain caves and recording underground passages in cuneiform, something was happening at the opposite edge of their world. The third zone is beneath the Persian Gulf, and this is the one that stirs the most debate. The Abzu wasn’t described as just an underground freshwater ocean.
It was the original home of Enki, the god of wisdom, water, and creation. Its location was specific, where freshwater met saltwater, where the Tigris and Euphrates rivers emptied into the sea. 5,000 years ago, the Persian Gulf coastline looked wildly different. Sea levels were lower. What is now shallow ocean floor was dry land, river delta, marshland, and land people could live on.
The change was slow, but massive. As ice age glaciers melted and sea levels rose over thousands of years, entire coastal stretches were swallowed by the Gulf. Any structures, settlements, or natural features on that ancient coastline are now underwater. Huge freshwater springs still flow from the seafloor in the northern Persian Gulf.
These are the remains of the ancient freshwater system that once surfaced on dry land, the literal Abzu, freshwater rising from beneath the earth at the point where it met the salt sea. Divers in the region have seen these springs firsthand. Cold freshwater flows visibly upward through warm saltwater, creating shimmering columns visible from meters away.
To someone watching this thousands of years ago, when these springs were on dry land or in shallow coastal waters, it would look exactly like the earth itself was pushing water up from its core, which is exactly what the Sumerians said was happening. In the early 2000s, marine archaeologists surveying the Gulf floor found strange patterns in the region where the ancient Tigris-Euphrates meeting point would have been.
Sonar readings showed shaped formations on the seafloor at depths between 20 and 40 m, formations that didn’t match natural processes. The formations were even evenly spaced and made of material denser than the surrounding mud and sand. No formal dig has taken place. The political headaches of doing marine archaeology in waters claimed by multiple nations, combined with how touchy oil drilling rights are in the same region, has stopped any government from giving the green light.
The sonar data was published in a 2006 marine geology survey. The bottom line was clear, the formations deserved a closer look, but the political and economic barriers made it unlikely any time soon. So, this is what we’re looking at. The Babylonian map of the world, the oldest known attempt to draw the entire planet, doesn’t just show the surface.
It’s eight triangular nagus describe lands beyond the known world, and at least three of those descriptions match real features tied to passages beneath the surface. The Zagros cave systems, still open and still not fully explored, the sealed cave beneath a Bronze Age site in eastern Turkey, recorded but unfunded, and strange shapes on the floor of the Persian Gulf in the exact spot the Sumerians said the Abzu could be entered.
Now, let’s deal with the obvious question. Does this mean the Sumerians and Babylonians knew about a real inner world? No. Modern earth science has fully mapped the planet’s inner layers through earthquake wave study. There are no hollow spaces large enough to count as an inner world in any real sense. What there are, however, are cave systems of extreme size that ancient peoples found, explored, and wrote down using the language and belief systems they had.
Consider the scale of what the Sumerians ran into. The Zagros Mountains alone hold limestone cave systems that reach hundreds of meters below the surface with chambers large enough to hold small lakes and underground rivers that flow for kilometers before coming out at distant springs. Some of these systems keep their own air conditions, temperatures that stay the same year-round no matter what the weather is on the surface, moisture levels that create lasting mist in certain chambers, and air that differs noticeably from the air above ground.
Carbon dioxide levels in deep caves can climb high enough to cause dizziness, confusion, and eventually passing out, something that ancient texts describe as the breath that steals life or the air that brings sleep. Modern cavers spot these warnings right away. Ancient travelers would have read them as divine protection, the gods guarding their domain against unwelcome entry.
To a Sumerian merchant traveling the tin roads or a Babylonian scribe gathering travel data, these cave systems would have been impossible to tell apart from an entrance to another world. The endless darkness, the sound of rushing water where no water should exist, the glowing minerals set in cave walls creating what would look like stars in an underground sky, these aren’t supernatural events.
They’re natural realities that ancient observers understood through the lens of their existing beliefs about gods, the underworld, and how the world was built. What makes the Babylonian Map of the World extraordinary isn’t that it proves the existence of an inner world, it’s that it proves ancient Mesopotamians were carefully recording these findings and building them into their most advanced maps and records.
The Nigu aren’t fairy tales stuck onto the edge of a map, they’re data, real-world data recorded with measurements and distances gathered by scribes whose entire training was built around getting things right. The fact that we can take 2,600-year-old travel descriptions and match them to real natural features isn’t proof of ancient alien knowledge or hollow earth theory.
It’s proof that the people who created this map were better observers and more careful record keepers than we’ve given them credit for. They found something extraordinary beneath the mountains and beneath the sea. They wrote it down. And then we spent 130 years assuming they were making it up. The Zagros cave systems remain the easiest to reach of the three overlap zones.
The Alisadr complex is partly open to visitors, though only a small part has been explored. Deeper sections are sealed off, officially for safety reasons, though local guides will tell you that dig teams who entered the deeper chambers in the 1970s found carved walls and artifacts that were taken out and never publicly recorded.
The Iranian Cultural Heritage Organization has neither confirmed nor denied these claims. The cave in eastern Turkey remains sealed beneath its collapsed Bronze Age structure. No permits for further digging have been issued since the original 2011 survey. The lead archaeologist on that project moved to a German university and has not published further on the site.
And the Persian Gulf shapes sit untouched beneath 30 m of water in a politically tense zone where archaeology takes a permanent backseat to oil. Three points on a map. Three passages described in cuneiform by people who lived and died before the Roman Empire existed. Three locations where the surface world gives way to something beneath it.
Something the ancients thought important enough to include on the only world map they ever made. One of those passages is in a cave system you can physically walk into today. The others are sealed, unfunded, or underwater, but recorded well enough that we know exactly where they are. The Babylonian map of the world sits in case 15 of the British Museum’s Mesopotamian gallery.
It’s small, broken, and easy to overlook. The cuneiform is faded. The triangular nagu along its edges are chipped and incomplete. Visitors glance at it and move on. But if you know what those triangles stand for, if you understand that the scribes who carved this tablet were recording locations, not fantasies, then you’re looking at something that hasn’t been fully reckoned with.
A 2,600-year-old chart that points to places beneath the surface of the earth and says, in the oldest written language on the planet, here is where you enter. We found two of those entrances, we recorded them, and then we sealed them, defunded them, or simply stopped looking. The third one is still open. It’s in the mountains where the Sumerians said it would be, and the deepest sections have never been mapped.
The map told us where to look. We just stopped reading it. The scribe who carved BM 92687 was a man named Iabbel-ili from the city of Borsippa. His colophon at the bottom of the tablet tells us he was copying an older document, keeping alive knowledge that was already ancient when he pressed his reed stylus into wet clay.
He didn’t invent what’s on that tablet, he inherited it, and he thought it important enough to copy it exactly for whoever came after him. We came after him, and we’re only now starting to understand what he was trying to tell us. If ancient mysteries like this are your thing, you need to see what I’m covering next week.
