In 1951 , a small airstrip was built at the ruins , which previously could only be reached by several days ' travel through the jungle on foot or mule . In 1956 the Tikal project began to map the city on a scale not previously seen in Maya no area . From 1956 through 1970 , major archaeological excavations were carried out by the University of Pennsylvania Tikal Project . They mapped much of the site and excavated and restored many of the structures . Excavations directed by Edwin M. Shook and later by William Coe of the university investigated the North Acropolis and the Central Plaza from 1957 to 1969 . The Tikal Project recorded over 200 monuments at the site . In 1979 , the Guatemalan government began a further archeological project at Tikal , which continued through to 1984 .