 Tikal has been partially restored by the University of Pennsylvania and the government of Guatemala . It was one of the largest of the Classic period Maya cities and was one of the largest cities in the Americas . The architecture of the ancient city is built from limestone and includes the remains of temples that tower over 70 metres ( 230 ft ) high , large royal palaces , in addition to a number of smaller pyramids , palaces , residences , administrative buildings , platforms and inscribed stone monuments . There is even a building which seemed to have been a jail , originally with wooden bars across the windows and doors . There are also seven courts for playing the Mesoamerican ballgame , including a set of 3 in the Seven Temples Plaza , a unique feature in Mesoamerica . 
