Archaeological Mysteries of the United States


Mystery Hill: America’s Stonehenge-Salem, New Hampshire

Mystery Hill is known as “America’s Stonehenge” even though it doesn’t quite resemble the prehistoric monument located in the United Kingdom. Instead, the site consists of a number of large rocks and stone structures scattered around 30 acres in the town of Salem, New Hampshire. It has been stated that these complex caves and stones are only as old as the 17th century. However, it isn’t known how old the stones really are because the ruins have reportedly been tampered with at the hands of a 1930s landowner. It is believed that the man was convinced the structures were the remains of a 7th century Irish monastic colony. He was so convinced by this, the landowner would “fix” parts of the structures. Today, Mystery Hill is opened to the public for a small fee.

Casa Grande Ruins- Coolidge, Arizona

The Casa Grande Ruins is one of the largest prehistoric structures ever built in North America. The ruins remain a mystery, but archaeologists do know that the structure, which is said to be an ancient Pueblo People’s Hohokam structure, was probably constructed in the early 13th century. Builders used adobe and the full compound included many other adobe structures. What archaeologists still don’t know is what the structure was used for. Some believe it could have been a guard tower, a house of worship, or something else. Other historians believe that the Casa Grande functioned as an astronomical observatory since the four walls face the points of the compass with some of the windows aligned to the positions of the sun and moon.


Hemet Maze Stone- Hemet, California

The Hemet Maze Stone is a prehistoric petroglyph. The maze has two rectangular boxes– one large one surrounding the maze and one located in the center of the maze. Reasoning behind the design is unknown to this day. The Maze Stone is unlike any other maze we usually see, even though it certainly looks like one. Without knowing the creator, we do not know if the design represents an engineering drawing, a symbol, or something else. Archaeologists have found other instances of where this pattern is used in the U.S., all of them located in California.

Berkeley Mystery Walls- San Francisco, California

The East Bay Mystery Walls stretch for over 50 miles and are found down the hills of the East Bay from Berkeley to San Jose. These ancient stone walls are a mystery because no one knows how old they are, who built them, or why they built them. In some places, the stone walls reach up to five feet tall. One would assume the walls were built to block enemies or used as a defensive method; however, they are not continuous or high enough to act as an enclosure. Early Spanish settlers found them and a 1904 archaeologist suggested they were built by Mongolian sailors.


The Great Serpent Mound-Hillsboro, Ohio

The Great Serpent Mound of southwest Ohio is the world’s largest serpentine effigy mound discovered. The serpent averages about 1,330 feet in length and 3 feet in height. There are tons of speculations on how the serpent came to be. It is thought by most people that the serpent is about to swallow an egg. However, others believe it represents an eclipse. It was first spotted by European settlers in 1812, and was left untouched until the Smithsonian sent two surveyors out to map the site in the 1840s. Scholars still are unsure of the mound’s purpose.

Bighorn Medicine Wheel-Lovell, Wyoming

The Bighorn Medicine Wheel is an American Indian sacred site in Wyoming. While there are several medicine wheels scattered around North America, Wyoming’s Bighorn is the biggest at 75 feet in diameter. In the 1970s, Astronomer John Eddy noticed that some of the spokes pinpoint to the direction of the sunrise, and other spokes of the wheel mark the rising point of other stars, suggesting that the sacred site may have been used as an observatory. It remains a mystery on who built the wheel and why.

Share this!

Leave a Reply