what is a peninsula

A peninsula is a piece of land that extends from a mainland and is surrounded by water on most, but not all of its borders. It is also sometimes defined as a piece of land bordered by water on three of its sides. Peninsulas can be formed from continental drift, glacial erosion, glacial meltwater, glacial deposition, marine sediment, marine transgressions, volcanoes, divergent boundaries or river sedimentation. The surrounding water is usually understood to be continuous, though not necessarily named as such. The worlds largest peninsula is Arabia, covering about 1 million square miles (2.6 million square km) in Southwest Asia. Other notable peninsulas include the Malay Peninsula in Southeast Asia, the Korean Peninsula, the Iberian Peninsula in Europe, and the Yucatán Peninsula in North America.