Faces signifying the victims of human sacrifice stare ominously from a tzompantli in the Museo de Templo Mayor in Mexico City. The word means “skull rack” in Nahua. Tzompantlis were used by many Mesoamerican cultures to appease the gods. The Templo Mayor was built by the Aztecs to honor the war god Huitzilopochtli and the rain god Tlaloc. Click the above image to enlarge, click to view my high-resolution photo gallery, or click to read my travel guide “A Weekend Guide to Mexico City’s Centro Histórico.”