Monasterio Museo Santa Catalina de Siena

Guided tours (in Spanish) of the museum at this fully functioning Dominican monastery, founded in 1592, take in 18th-century religious paintings, some of which are downright gruesome. To this day, the nuns here have only one hour each day to talk to each other or watch TV. But they make all sorts of natural products (shampoos, wine, hand cream and more), which you can purchase from a rotating door that keeps the nuns hidden.