A pier is a raised structure that rises above a body of water and usually juts out from its shore, typically supported by piles or pillars, and provides above-water access to offshore areas. Frequent pier uses include fishing, boat docking and access for both passengers and cargo, and oceanside recreation. Bridges, buildings, and walkways may all be supported by architectural piers. Their open structure allows tides and currents to flow relatively unhindered, whereas the more solid foundations of a quay or the closely spaced piles of a wharf can act as a breakwater, and are consequently more liable to silting. Piers can range in size and complexity from a simple lightweight wooden structure to major structures extended over 1,600 m (5,200 ft). In American English, a pier may be synonymous with a dock.

The Margate Jetty was a pier in Margate, Kent, in England initially constructed of wood in 1824. It was rebuilt in iron in 1855 and extended and added to over the years. It closed in 1976 over safety concerns and was severely damaged in a storm two years later. Demolition took many years and some parts remained until 1998.