Map of the city of Tikal, in northern Guatemala, which has been restored over the course of a century.
Picture of Temple I and Temple II (see map)
The "gravestone" like objects are "stele", which have carved images and text written by the Maya. To create a hard, flat surface on which to build their temples, they created a concrete slab of ground limestone. In Tikal, they had also built large artificial lakes, lined with this limestone concrete. 