Archaeologists from the Research Center of the Slovenian Academy of Sciences and Arts have found two ancient Mayan cities hidden in the jungle of southeastern Mexico, and they believe there are more to be found in the region.

As reported by a number of news outlets, Ivan Sprajc, associate professor at the Research Center of the Slovenian Academy of Sciences and Arts, said his team found the ancient cities of Lagunita and Tamchen on the Yucatan peninsula in April by examining aerial photographs of the region

Archaeologists believe that the two cities reached theirheyday in the Late and Terminal Classic periods (600-1000 AD). At each site, researchers found palace-like buildings, pyramids and plazas. One of the pyramids is almost 20 meters (65 feet) high

Researchers also found a facade featuring a monster-mouth doorway, which probably marked one of the main entrances to the center of the city. “The entrance apparently symbolizes the entrance to a cave and to the underworld. The sites have not been excavated yet.

Last summer, Sprajc discovered another ancient Mayan city, Chactun, 10 km (6 miles) north of Lagunita and 6 km (4 miles) northwest of Tamchen.