The largest ever construction of the Mayan civilization has been unearthed in Mexico’s Tabasco State roughly 850 miles east of Mexico City.

The finding consists of a platform topped with a 13-foot tall pyramid and multiple other structures which date from the early Mayan civilization roughly 3,000 years ago, according to a new paper in the journal Nature.

The ruins have been sitting in plain sight, but have laid undiscovered amid the region’s dense ranch lands.

“It’s fairly hard to explain, but when you walk on the site, you don’t quite realize the enormity of the structure,” the lead author of the paper told National Geographic. “It’s over 30 feet high, but the horizontal dimensions are so large that you don’t realize the height.”