Historic Alfama District, Lisbon, Portugal, 2002Photograph by Tino SorianoLisbon's Alfama District rises dramatically to the base of the imposing Saint George's Castle. The castle began as a Visigoth fortification in the sixth century and was taken over in turns by the Romans and the Moors. It was eventually captured by Portugal's first king and became the royal palace. Tourists flock to the castle's towers and ramparts, which offer unsurpassed views of the city below.