A peculiar thing, which looks like part of a mythical abandoned aquarium, built in the Stone Age 5,500 years ago has puzzled archaeologists.

During the survey of Lake Constance in Northern Europe, archaeologists discovered extremely puzzling rock structures at the bottom of the lake. Many stones with a width of more than 2.5 m are arranged in a strange architectural style, described as similar to the famous Stonehenge stone ring in the UK, so it was named “Swiss Stonehenge” by the media.

Part of the Stone Age structure was exposed when the sediment was removed – photo: CEN

The excavation process has revealed up to 170 giant stone blocks. At first, the rocks were thought to be a bizarre arrangement of nature, created by glaciers 18,000 years ago. But the analysis steps show that this strange cluster of structures is completely man-made, dating back to about 5,500 years ago, which is in the Stone Age. Most of the rock formations are buried a few meters below the sediment at the bottom of the lake.

Divers are approaching the area where the giant stone ring was discovered – photo: CEN

A log is said to be a remnant of the construction – photo: CEN

A spokesman for the Archeology Office of the State of Thurgau – Switzerland, which is excavating the lake bed, said the discovery was “sensational”.

Researchers have come up with many theories regarding the mysterious cluster of structures: it could be a dam, burial mounds, or the service of ancient sea routes… But either way, it is still incredibly amazing and puzzling at 5,500 years old.

Photo: CEN

Excavators were taken by boat to the center of the lake to help remove the sediment that buried the mysterious structure – photo: CEN

Photo: CEN

According to archaeologist Urs Leuzinger, a member of the research team, when built, the rock formations could have been along the coast or in shallow water, before geological processes submerged the area in deep water.

Mr. Leuzinger also said they are continuing to dig the area in the hope of finding other artefacts that will further elucidate the theories. They also suspect that there are also ancient settlements buried farther from the shore in Lake Constance.

Lake Constance has an area of up to 536 km2, bordering the countries of Germany, Austria and Switzerland. The discovery occurred at a depth of about 4.5 meters near the shore of Switzerland.