In less than two years, one team of Mexican and international archaeologists located three ancient Mayan cities that had been taken over by the earth for decades.

All three sites were found in the Biosphere Reserve of Calakmul in the Mexican region of Campeche. Head archeologist Ivan Šprajv of the Slovenian Academy of Sciences and Arts led the team into the depths of the jungle after locating sites through aerial views. The first site, Chactún, was discovered in June of 2013. The 54-acre site was thought to have been a central governing city that existed around 1400 years ago and was home to between 30,000 and 40,000 people.

The second and third sites — Lagunita and Tamchén — were found just recently. Lagunita was home to a monument of a Mayan monster said to have been associated with the underworld, water and fertility. Archaeologists also unearthed a Mayan ball court and a 65-foot pyramid. In Tamchén, the team found several deep underground storage structures known as chultunes as well as a temple.

Since the Southeast Campeche Archaeological Recognition Project was launched nearly two decades ago, archaeologists have located 80 sites throughout the area, according to EFE.