American English 5 - Unit 2 - The Yonaguni Monument

The Yonaguni Monument is a submerged rock formation discovered in 1986 by Kihachiro Aratake, a local Japanese diver and tour operator, when he was searching for new dive sites near Yonaguni Island, the westernmost island of Japan, about 25 meters below sea level.

As soon as the formation was noticed, its unusual features sparked interest. It became famous because its large, flat terraces, sharp right angles, straight edges, steps, and structures resembling platforms and roads look like man-made architecture.

At that time, and later, some researchers began to argue that it could be the remains of an ancient, lost civilization. The most prominent supporter of this idea is Japanese marine geologist Masaaki Kimura, who suggests that the monument was carved by humans more than 10,000 years ago, before sea levels rose at the end of the last Ice Age. Back then, a long time ago, the site would have been above water. If this theory were correct, it would predate known civilizations in Japan and, as a result, radically alter our understanding of early human history.

Meanwhile, during ongoing geological studies, most geologists and archaeologists have argued the opposite, claiming that the monument is a natural formation created by tectonic activity, erosion, and the way sandstone fractures along straight planes, which can naturally produce angular shapes.

Until now, no tools, carvings, inscriptions, or artifacts have been conclusively found to prove human construction. Afterward, and even today, the site remains controversial; finally, it stands at the boundary between geology and archaeology, fascinating observers while still lacking definitive evidence of human involvement, making it one of the most debated underwater sites in the world.

Before its discovery, life on Yonaguni Island was quiet, isolated, and largely unchanged for generations. The island was known mainly for farming, with a strong sense of community shaped by geographic remoteness and frequent typhoons. Residents preserved local traditions, dialects, music, and rituals, while everyday life followed a steady rhythm. Diving existed at the same time, but only on a modest, recreational scale, and Yonaguni rarely appeared in national or international media. Then, after the monument was discovered, this calm rhythm changed dramatically. During the years that followed, scientists, divers, journalists, and tourists arrived, and later, Yonaguni was transformed from a little-known border island into a global subject of debate about ancient civilizations – something that profoundly changed its economy, visibility, and relationship with the outside world.