Chile's second-largest city, roughly 830 miles north of Santiago, is built on maritime trade and mining. Today, ancient piers molder picturesquely at the port. In the Barrio Histórico nearby, you can stroll through a plaza of Victorian and Georgian buildings, amid the city's jumble of one-way streets and modern malls. Plaza Colón offers fountains, flowers, palms, an evocative clock tower, and a neo-Gothic cathedral. An attractive old customs house is now a museum of archaeology and local history. East of Antofagasta, the Atacama Desert is the driest place on Earth, and the silence here can be deafening. Natural wonders include geysers, glaciers, and valleys that resemble the surface of the moon.