"The marigold façade of the Pousada Convento in Tavira, a town on Portugal's southern coast, gleams in the late-afternoon sun. Refreshing as it is to sip chilled pineapple juice in the Algarve heat, it's not the promise of shade that leads me into its cloisters. The tranquil courtyard, flanked by cheery yellow walls and weathered colonnades, is a portal to the 16th century, when the structure was built for an order of Augustinian nuns."