Is it safe?
Mexico City is home to some 20 million people, and safety varies dramatically between different zones and neighborhoods. It is best to stay in neighborhoods like Centro, Roma, and Condesa which are considered very safe and to avoid the shadier parts of town including Tepito, La Lagunilla, Doctores, and Mercado Merced.
Travelers should take sensible safety precautions like not flashing expensive items and drinking in moderation, but Mexico City is safe and receptive to tourists. For an up to date assessment check the latest US State Department Travel Advisory.