A peninsula is a piece of land that is almost entirely surrounded by water, but is connected to a larger landmass. It is essentially a large projection of land extending into a body of water.

Here are some key features of a peninsula:

* Connected to a mainland: A peninsula is attached to a larger landmass, unlike an island which is completely surrounded by water.

* Surrounded by water on three sides: The majority of the peninsula's borders are defined by water, with only one side connected to the mainland.

* Protruding into water: Peninsulas extend outward into a body of water, such as an ocean, sea, lake, or river.

Examples of famous peninsulas include:

* The Iberian Peninsula: Home to Spain and Portugal, it juts out into the Atlantic Ocean.

* The Italian Peninsula: The "boot-shaped" peninsula in the Mediterranean Sea.

* The Korean Peninsula: Dividing the Yellow Sea and the Sea of Japan.

* The Florida Peninsula: Extending southward into the Atlantic Ocean and Gulf of Mexico.