Ancient Mysteries · Ancient Alien Theory
The Yonaguni Monument
A sunken formation of terraces and right angles.
📍 Yonaguni, Japan
Ancient Mysteries · Ancient Alien Theory
A sunken formation of terraces and right angles.
📍 Yonaguni, Japan
Off the coast of Japan lies a drowned formation of flat terraces and sharp angles — natural rock, or a lost monument?
Off Yonaguni, the southernmost of Japan's Ryukyu Islands, divers in 1986 found a huge submerged formation of flat terraces, straight walls and sharp right angles, rising some 90 feet from the seabed. If it was shaped by human hands, it stood above water more than 10,000 years ago, at the end of the last Ice Age.
The formation shows a possible staircase and features some describe as a carved face and channels. Marine geologist Masaaki Kimura argues it is a man-made monument; others, including geologist Robert Schoch, hold that Yonaguni's sandstone naturally fractures along straight, blocky lines — and the debate has never been settled.
Geologists are split. Some see natural fracturing; others point to the steps, the right angles and the apparent carvings as signs of a civilization far older than any we know. If it is man-made, it rewrites the timeline of monumental building.
What makes it unique on this list: Yonaguni is the wild card — the only candidate here that, if human-made, would be far older than every other site and would prove an advanced culture existed before the last Ice Age ended.
What would need to be answered to put the mystery to rest:
Reached by dive boat from Yonaguni Island in Okinawa Prefecture — an advanced-diver adventure to one of the ocean's great mysteries.
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