posting here a little late lol, but hopefully it helps someone out....

i've visited Romanza gym in Mexico City once, to see Juan Manuel Marquez before his second fight with Manny Pacquiao, met Abner Mares there when he was still training with Nacho

it's a must visit for hardcore boxing fans. Mexico City is a great, great city, lots of fun, just got to be careful...

Romanza gym is in: Colonia Iztacalco, between the streets Anil and Resina

if you're up for adventure during the DAY, do not go at night, you take the brown metro line to Hippodromo stop, make your way out and take a taxi, tell the taxi driver the names of those two streets, don't stop for anyone in the metro and walk FAST, FAST, to avoid any problems. it will probably take you an hour to get there this way

if you take the metro, DO NOT WEAR A WATCH, or take your ipod, etc with you. dress plain and walk fast to stay under the radar

taking a taxi to the gym is safer but more expensive, probably around $40 roundtrip or more, negotiate with a trusty taxi cab from your hotel, taking the metro is more dangerous but more exhilarating lol