As unique and historic, in its way, as the more famous Edgar's, the Muralla is an athletic club founded in 1920 and recently opened to the public. A step inside the courtyard of the 19th-century building shows almost a century of trophies and their rowing shell. The Muralla is also a bit of Carnival history, having hosted the Carnival Monday Ball and Coronation of the Queen of the Pacific for several decades. To the right is a dark, air-conditioned bar with some of the cheapest beer in town (and great tamales from 3-6pm on Thursday, Friday and Saturday), but most foreigners prefer the Old-World courtyard in the evenings, where there is usually a band, either cowboys or romantic/pop. If your idea of "the real Mexico" is a bunch of guys in red satin cowboy clothes playing polka-based shitkicker ballads about treacherous women and the narcotics business--and that's actually about as real as Mexico gets in many ways--this is the spot.
Bar service from 10am to midnight Monday to Saturday. There is no phone, and the courtyard occasionally closes due to club events--but it's only steps away from Olas Altas, so you won't have to go thirsty.