GETTYSBURG, Pa. - A New Jersey geologist says that he has discovered evidence of ancient calendars in Gettysburg, Pennsylvania.

John Anton tells News 12 New Jersey that he made the finding while walking through an area of the historic national park known as Devil’s Den.

“I saw a rock that made me stop dead in my tracks... and I said ‘Wow, this is what I would expect from a calendar,’” he says.

Tests have showed that the rock formation was an ancient calendar. On the first day of summer and winter, the sun lines up perfectly inside a triangle in the rocks. Inside the opening was an ancient sundial covered with carvings known as petroglyphs.

Anton also discovered another ancient calendar in Gettysburg on the mountain known as “Little Round Top.” This calendar charts the beginnings of spring and fall. The stones, piled on top of one another, each weigh 15 to 25 tons.

Anton estimates that the calendar was built between the years 1 and 1,000 A.D. 

“Someone put this together,” he says. “The fact that they took the time and effort to put this together means that it meant something very important.

Anton says the structures look like ones that have previously only been found in Europe and Asia and could be evidence that Europeans and Native Americans interacted hundreds of years before originally thought.