This cool, rambling colonial edifice was built as a Dominican convent in the 1740s. (Before that, the site held one of Mexico’s first hospitals, founded by Vasco de Quiroga.) Today it houses small artesanías (handicrafts) shops, each specializing in a particular regional craft. Renovations over the years mean there are now five patios rather than the previous 11 (as in the market's name – once is Spanish for 'eleven').
Look for copperware from Santa Clara del Cobre and musical instruments from Paracho, as well as lacquerware, hand-painted ceramics and vibrant textiles. Be sure to check out the Baño Barroco, a 16th-century bathing room.