"Tlatelolco One of Mexico City’s most historic neighborhoods—a once-independent city-state politically joined to the Aztec capital of Tenochtitlan—Tlatelolco is a fascinating side trip few tourists make. At its center lies the district’s so-called Square of the Three Cultures, where a colossal public housing development (of revitalized interest to architecture buffs) surrounds a 17th-century Spanish church (notably embellished with stained-glass windows by 20th-century artist and architect Mathias Goeritz) as well as the ruins of pre-Hispanic Tlatelolco pyramids and other structures. In addition to being the exact spot on which the Aztec empire fell, the square was also the site where Mexican armed forces perpetrated a bloody 1968 massacre of university students and political activists. Tragedy aside, the area is still home to thousands of hardworking average Joes, and the community garden, known as the huerto , is pure down-home bucolic charm; it’s well worth a pop-in."