Mexicans are taught to revere their pre-Columbian roots. So some archaeologists are outraged by what they view as the government’s failure to safeguard the nation’s Mayan palaces and Aztec pyramids.

A recent decision by the government to erect a glass and steel facade on a portion of the historic Fort of Guadalupe in Puebla in time for the Sept. 15 Mexican independence celebrations was the last straw. The archaeologists have occupied Mexico’s prestigious National Museum of Anthropology, telling museum-goers that taking liberties with federally protected buildings was becoming commonplace.