Harbor is any sheltered body of water where ships may moor or anchor. Natural or landlocked harbors are found in bays and inlets where arms of land form a natural protection from waves and winds. Artificial harbors are made by erecting stone or steel breakwaters.
Large harbors are lined with quays, piers, and docks at which ships can be loaded and unloaded. A quay (wharf) is a stone or wood platform built along the shoreline, a pier is a platform that extends well out into the water, and a dock is the space between piers.
Some of the world’s most beautiful harbors are at Rio de Janeiro, Brazil; Naples, Italy; and San Francisco. The world’s busiest harbors include those at Hong Kong, China; Rotterdam, the Netherlands; Shanghai, China; and Singapore.