Underwater Pyramid in Wisconsin

There’s an underwater Pyramid in Wisconsin!

Underwater structures can be found in multiple areas around the world. These range from sunken monuments and temples, to even roads and large buildings. But why should we care about these underwater structures?

underwater pyramid in rock lake wisconsin

 Due to murky water conditions, the structures are rarely visible, even with high tech equipment, but fisherman and divers do catch glimpses of the mysterious structures from time to time and the Rock Lake Research Society has documented their existence using sonar and aerial photography.


Based on ocean levels as a form of dating, the location of some of these structures would mean that they were built many thousands of years ago. Some, as far back as 10,000 or even 20,000 years ago. According to history as we know it, we were still hunting and gathering at that time, and certainly not building extravagant structures.

So who are these mysterious builders from a forgotten civilization?

Many of us are likely somewhat familiar with the Yonaguni Monument in Japan, or even the Bimini Road in Bermuda. Here’s yet another less heard of pyramid that just happens to be resting at the bottom of a lake.

Underwater Structures in Rock Lake?

The first encounter with this strange sunken pyramid was in the early 1900s when Claude and Lee Wilson mentioned their oar striking a large structure, roughly 6 feet below the surface of the water. At that time, the men attempted to locate the structure but to no avail.

In the mid-1930’s, divers again came in contact with a strange underwater structure in Rock Lake, USA. This time, it attracted the attention of a geology professor and the director of the Wisconsin Historical Museum.

In 1937, engineer and diver Alex Max Gene Nohl finally managed to locate the structure. To his astonishment, it was indeed a pyramid! This rekindled the public’s interest in the subject. However, no archaeologist or scientist would take it seriously (as sadly always seems to be the case.)

Experts estimated the age of the lake to be roughly 10,000 years old, which would make the pyramid beneath the lake at least that old. This alone was enough to cause academics to turn a blind eye, rather than have to rethink the what the existence of such a structure might mean.

30 years later, in 1967, the first sketch of the pyramid emerged. For the next several decades, a combination of divers sketches, photographs, and sonar scans finally managed to map the contents of the lake.

rock lake underwater pyramid sketch

According to Frank Joseph, who at this point has written 2 books about the Rock Lake structures, there are at least 10 monuments beneath the surface. Two such monuments have been mapped out so far. The largest has been named Limnatis Pyramid, measuring about 18 feet in height and 100 feet in length.

Understanding the Pyramids beneath Rock Lake, Wisconsin

The southern end of Rock Lake near Aztalan State Park in Wisconsin is the site of an explainable series of rock formations that has baffled everyone who has seen them for centuries.

   When European settlers first took up residence in the area, Native Americans told them of rock teepees located on the lake’s floor. In 1900, their existence was verified when local duck hunters caught site of the massive monoliths from their boat. Entirely submerged, the structures are 30 feet high and 100 feet long, and are conical in shape.​

   Explanations for the underwater stone pyramids vary. Some say that they are simply natural glacial formations, while others say that they are manmade, and were constructed by an ancient civilization before the area was flooded with water. Proponents of this theory point to the archaeological evidence found nearby in Aztalan State Park, where the Mississippian Indians constructed pyramidal mounds over 1,000 years ago.

The following passage comes from the Rock Lake Research Society, an organization dedicated to the investigation and documentation of these enigmatic structures:


  “1900: Two local residents, the Wilson brothers, spot mysterious structures underwater while duck hunting. Unusual clarity exists as it is late fall and rainfall was low for the year dropping water levels below normal. The two men advise the other residents of Lake Mills and dozens of people in boats converge on the lake to witness the underwater structure. Several boys dive a short distance and touch the pyramidal structure. It is described as a long tent-shaped structure of undetermined height and approximately 100 feet long. The next day water conditions change and the structures are lost to the murkiness and silt of the lake.


   Lake Mills then becomes a center of statewide attention as newspapers run articles.


   Famous Diver Max Nohl, the true inventor of the ‘SCUBA’ tests his equipment in Rock Lake. He comes upon a tall cone shaped pyramid in the south end of the lake. The structure made of small stones looked like an upside down ice cream cone that was definitely manmade according to Nohl. Nohl plans to come back to further explore the pyramid legends of Rock Lake. Nohl dies in car crash with wife several years later before he could return.”

Over 100 years since the stories of Rock Lake first emerged, we are only now beginning to get a picture of what it all means.

sonar scan of rock lake pyramids


 Aerial photos, side boat sonar scans, and underwater divers eventually charted a complex of at least nine different stone structures, including: two rectangular pyramids, several stacked–rock walls, two “Stone Cone” areas, a conical pyramid, and a large “Delta Triangle” structure. There is also a part of the lake floor that supposedly features Indian mounds similar to Aztalan, a prehistoric Mound Builder site located only two miles away. 

   The largest underwater structure, dubbed the Limantis Pyramid, has a length of about 100 feet (30 m), a base width of 60 feet (18 m), and a height of 24 feet (7.2 m), although only about 12 feet (3.6 m) protrude from the silt and mud of the lake floor. The Limantis Pyramid is a truncated tent–like pyramid, built largely out of rounded black stones. The cap stones on the two rectangular pyramids are squared rather than round. Small amounts of a plaster coating are still detectable, similar to the coating used on the Aztalan stockade walls.

The Native American site of Aztalan is located just 3 miles from Rock Lake. At the site, are two similar shaped pyramids, surrounded by a tall blockade. This gives us a bit of an idea of where these structures may have come from.

The Aztalan State Park has now achieved a National Landmark status. Some speculate that Aztalan may be an extension of the much better known pre-Columbian city of Cahokia.

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