Caldera, a seaport town of Chili, in the province of Atacama, 52 m. W. N. W. of Copia-po, in lat. 27° S., Ion. 70° 57' W.; pop. between 3,000 and 4,000. The town was built about 1840 to serve as an outlet for the mineral products of the region round about Copiapo, and is very prosperous. The streets are regular and wide, and many of the dwellings and public edifices handsome; but the inhabitants suffer much from the want of suitable drinking water, which hitherto could be procured only by distilling sea water. In 1872 the authorities began to take measures for the introduction of good water by pipes from the highlands beyond the desert which forms a large part of the province. A railway about 95 m. long connects Cal-dera with Copiap6 and San Antonio. The bay, though in general shallow, is well sheltered, has a lighthouse at the S. W. entrance, and a commodious mole of recent construction. Trains run to the end of the mole. In 1867 the clearances were 350; tonnage, 264,110.