Artificial island

An artificial island or man-made island is an island that has been constructed by people rather than formed by natural means. They are created by expanding existing islets, construction on existing reefs, or amalgamating several natural islets into a bigger island.

Early artificial islands included floating structures in still waters, or wooden or megalithic structures erected in shallow waters (e.g., crannógs and Nan Madol discussed below). In modern times artificial islands are usually formed by land reclamation, but some are formed by the incidental isolation of an existing piece of land during canal construction (e.g. Donauinsel and Dithmarschen), or flooding of valleys resulting in the tops of former knolls getting isolated by water (e.g. Barro Colorado Island). The largest artificial island, René-Levasseur Island, was formed by flooding of two adjacent reservoirs.

Some recent developments have been made more in the manner of oil platforms (e.g., Sealand and Republic of Rose Island).

Artificial Island, New Jersey

Artificial Island, New Jersey and Delaware, is an American island located along the eastern shore of the Delaware River and mostly in southwestern New Jersey with a tiny portion inside Delaware boundaries, and is part of Lower Alloways Creek Township, Salem County, New Jersey. It is separated from the mainland New Jersey by Alloway Creek and Hope Creek. It is called "artificial" since portions of the island are composed of land reclaimed from Delaware Bay.

The island is geographically unusual since it contains one of two tiny exclaves of the state of Delaware, which is created by the Delaware-New Jersey land border crossing the northern tip of the island, an area that is completely cut off from the rest of Delaware across the Delaware River to the west, and has no road connections to it. New Jersey is separated from Delaware by the Delaware River except for these two areas, which has a land border. The only land access to this exclave at the north tip of the island is from New Jersey.