Way south of the pure, unadulterated hustle and bustle of the historic center, east of refined and residential San Ángel, and northwest of Xochimilco and its colorful canals lies Coyoacán, a neighborhood unlike any other in the megalopolis that is Mexico City.Once an artsy hangout for the movers and shakers of the day, like Frida Kahlo and her husband Diego Rivera, as well as a refuge for exiled Communists like Leon Trotsky (all three have house museums dedicated to their honor in the barrio ), Coyoacán is now a popular tourist hangout . . .