Yonaguni Monument

There are big rocks under the sea. They look like steps or walls.

Some people think people built them. They see things like roads or a stadium. One man thinks they are very old.

Other people think the water made them. The rocks have lines in them. Earthquakes can also crack the rocks into shapes.

Strong water moves around the rocks. This can wash them clean. This might make them look flat.

People like to dive there. They go to see sharks too. It is a very cool place to see.

Deep under the sea near Japan, there are strange rocks. These rocks are near the island of Yonaguni. People found them in 1986 while looking for sharks.

Some people think the rocks are man-made. A scientist named Masaaki Kimura thinks they are old buildings. He sees things like roads, walls, and even a stadium. He thinks they might be from a lost land.

Other scientists disagree. They think the rocks are natural. The rocks are made of sandstone. Sandstone is a type of rock that forms in layers. These layers can break into flat shapes.

Earthquakes can also help make these shapes. The island is in a place with many earthquakes. These quakes can crack the rocks into straight lines. Strong ocean currents also move around the site. The water can wash the rocks and make them look flat. This is called erosion. Erosion happens when water wears away rock over time. Scientists say these shapes look like other rocks on the island. They believe the sea and the earth made them.

Deep under the sea near Japan, there are strange rock shapes. This site is called the Yonaguni Monument. It sits off the coast of Yonaguni island. This island is the furthest south in the Ryukyu Islands. The rocks are about 100 kilometres east of Taiwan. Some people think these shapes are very special. They wonder if they were built by people long ago. This makes the site a very interesting place to study.

How did people find these underwater rocks? In 1986, a man named Kihachiro Aratake was diving. He was looking for hammerhead sharks. The area is a popular place to see sharks in winter. While diving, he saw shapes that looked like buildings. Later, a scientist named Masaaki Kimura visited the site. He led a group of scientists to look closely. He believes the rocks are man-made steps. He calls them monoliths, which are large single stones.

Many scientists have a different idea about the rocks. They think the shapes are made by nature. The rocks are made of sandstone and mudstone. These rocks formed about 20 million years ago. Geologist Robert M. Schoch says the rocks have many layers. These layers are called bedding planes. The rocks also have straight cracks called joints. These joints happen naturally in the stone. Earthquakes in this region can also crack the rocks. This can make them look like straight walls or steps.

There is a big debate about the age of the site. Masaaki Kimura once thought the site was 10,000 years old. He thought it might be part of a lost land called Mu. Later, in 2007, he changed his guess. He said the rocks might be 2,000 to 3,000 years old. He thinks they were built and then covered by the sea. Other researchers, like Takayuki Ogata, studied the rocks in 2019. They used digital models to look at the shapes. They found that the rocks look like buildings but are natural. They saw similar shapes at other places on the island.

Even with the debate, people still visit the site. Divers travel there to see the amazing shapes. The ocean currents can be very strong there. A famous freediver named Jacques Mayol visited the site. He even wrote a book about his dives there. You can see similar shapes on land at Sanninudai. This helps scientists understand how the rocks change. It shows how water and wind work on the earth. The sea continues to shape the world around us.

The Yonaguni Monument is a mysterious submerged rock formation. It sits off the coast of Yonaguni, which is the southernmost island in the Ryukyu Islands of Japan. The site is located about 100 kilometres east of Taiwan. This underwater site is famous because people disagree about what it actually is. Some believe it was built by humans long ago. Other scientists argue that nature created these shapes through geological processes. This debate makes the monument a very important subject for study.

The discovery of the monument happened by accident in 1986. Kihachiro Aratake was a director for the Yonaguni-Cho Tourism Association. He was diving in the area to find hammerhead sharks. The sea near Yonaguni is very popular for diving during winter months. While looking for sharks, Aratake noticed seabed formations that looked like architectural structures. Soon after, a team of scientists led by Masaaki Kimura visited the site. Kimura is a marine geologist from the University of the Ryukyus. He claims the formations are man-made stepped monoliths, which are large single stones.

To understand the site, we must look at its geology. The formation is located below the Arakawabana cliff. This cliff is at the southern tip of Yonaguni island. The rocks are made of medium to very fine sandstones and mudstones. These belong to the Early Miocene Yaeyama Group. Geologists believe these rocks were deposited about 20 million years ago. Most of the rocks are connected to the underlying rock mass. They are not separate, freestanding rocks piled together.

Many experts believe the shapes are purely natural. Geologist Robert M. Schoch explains how the rock behaves. He observed that the sandstones contain many parallel bedding planes. These are flat layers where the rock can easily separate. The rocks also have many sets of parallel, vertical joints. Joints are natural fractures or cracks in the stone. Because Yonaguni is in an earthquake-prone region, these cracks can be very regular. Schoch suggests that the "walls" are just horizontal platforms. These platforms fell into a vertical position when the rock below them eroded.

There is a significant scientific debate regarding the history of the site. Masaaki Kimura once estimated the formation was at least 10,000 years old. He thought it might be part of a lost continent called Mu. In 2007, he revised this estimate to 2,000 or 3,000 years old. He believes tectonic activity caused the structures to be submerged. He claims to see a pyramid, roads, and even a stadium. However, archaeologist Richard J. Pearson believes this is unlikely. Other researchers, like Wolf Wichmann, also concluded the site was formed by natural processes.

Modern technology has provided more evidence for the natural theory. In 2019, Takayuki Ogata and other researchers used a digital elevation model. This is a computer tool used to map the shape of the land or sea floor. They also conducted geological field investigations of the rocks. They studied three specific locations called "geosites": Tindabana, Kube Ryofurishi, and Sanninudai. Their research showed the monument is a natural feature. It was formed by weathering and erosion acting on the bedding and joints. They found similar features at the Sanninudai geosite on the island.

Despite the scientific consensus, the monument remains a popular place for divers. The ocean currents at the site can be very strong. Famous freediver Jacques Mayol visited the site and wrote a book about his dives. Supporters of the artificial theory, like Graham Hancock, still argue the site is unique. They say it is unlikely to find so many strange shapes in one small area. They also note a lack of loose blocks on the flat areas. However, Schoch points out that strong currents likely sweep the rocks clean.

The study of the Yonaguni Monument connects to many different fields. It involves marine geology to understand the rock layers. It involves archaeology to debate human history. It also involves oceanography to study how currents and erosion work. Whether the site was built by hands or by nature, it shows how much we can learn from the sea.