In the northeast of Guatemala's Department of Petén is the site of San Bartolo, about 28 miles away from the site of Tikal. This site is now known to be the home of the oldest murals painted by the maya. After its discovery, San Bartolo was written on by National Geographic, published in their April 2001 issue.
San Bartolo is classified as a Formative period as well as a Classic period site. Multiple monuments exist, along with other items, that date from the Late Classic period. However, the majority of the site's buildings are Middle Preclassic buildings that people built over during the Late Preclassic period. It has been theorized that the San Bartolo was a living community from around 400 BC to around 400 AD.
At some point in the site's history, looters found out about the site and began to make various trips to it. Before its rediscovery, about 200 looting trenches were dug at San Bartolo.
Eventually, the site was officially rediscovered approximately eleven years ago, by an archaeologist named William Saturno -- one of the Peabody Museum's researchers -- in March 2001. He was working for the museum's Corpus of Maya Hieroglyphic Inscriptions, a project being directed by Ian Graham. Working with authorities, Saturno -- along with people such as Ian Graham and David Stuart -- began to work on the site.
San Bartolo extends to about half a mile in all directions. Over 100 stone structures have been discovered by Saturno and the people working with him at the site.
The main group of buildings at San Bartolo is called the Ventanas Group. Within the Ventanas group is a central plaza. A building named Structure 20 -- the tallest building of the group -- is on the north side of the central plaza.
Starting at the Ventanas Group and heading in a southerly direction is a causeway. East of the Ventanas Group is the Pinturas Group. Not as big as the Ventanas Group, this group has a pyramid about 85 feet tall that was built somewhere between 300 BC and 50 BC.
In an earlier building -- Structure 1 -- within a pyramid located in the Pinturas Group, Saturno accidentally discovered murals in a looter's tunnel. (This tunnel showed the pyramid was the last of about six previous buildings built on top of each other.) These murals, dating between 100 BC and 50 BC -- using the radio-carbon dating method --, are currently the oldest known murals in the ancient Maya world.
Another discovery was made at San Bartolo in 2005. The discovery was of another group of structures.
Not far from San Bartolo, a painted text has been discovered. This text appears to be similar to an undeciphered kind of Epi-Olmec (later Olmec) writing system found in the Isthmus of Tehuantepec. It is thought that the painted text was written between 300 BC and 200 BC.
"Historical Dictionary of Mesoamerica"; By Walter R. T. Witschey, Clifford T. Brown; 2011
"The Ancient Maya"; Robert. J. Sharer, Loa P. Traxler; 2006
"Oldest Mayan Mural Found by Peabody Researcher: Jungle Ordeal Leads to Surprise Treasure"; Alvin Powell; March 21, 2002