Uaxactún is an ancient ruin of the Maya civilization, located in the Petén Basin. The site is 40km north of Tikal. The Carnegie Institution conducted archaeological excavations here from 1926 to 1937. The excavations added greatly to knowledge of the early Classic and Pre-Classic Maya periods. The remains of several badly ruined late Classic era temple-pyramids were removed, revealing well preserved earlier temples underneath them. For most of the Carnegie team's time at Uaxactún, communication with the outside world was via a 4-day mule convoy to El Cayo, British Honduras. Towards the end of that time an airstrip was opened up. Flights to Uaxactún continued and a small village grew here, as it became a centre for gathering of chicle sap from the Petén jungle. In the late 1970s a rough road was opened up, connecting Uaxactún to Tikal and to Flores. Air flights were discontinued and in 1984 the road was improved. In 1982 Guatemala's Tikal National Park was expanded to include the ruins of Uaxactún within its protected area.