A modest entryway opens onto a bright, colonial Mexico fantasia, complete with blue tiles, crisp white linen, colorful pottery, and would-be-viceregal artworks. Since 1912, Café de Tacuba has opened early and stayed up late to serve classic Mexican fare like enchiladas and chalupitas, excellent tamales, hearty breakfasts, a wide variety of soups, and even more-ambitious entrees, attracting an amenable congress of families, foreigners, work groups, and confidence-exchanging senoras. Order the café con leche for a smart jolt of showmanship; Spanish troubadours serenade the proceedings most nights and weekends. Maybe it’s your grandmother’s Mexico, but the old girl knew a thing or two.