Common answers:

* Island: This is the most common answer, a piece of land completely surrounded by water.

* Peninsula: A piece of land that is mostly surrounded by water, with a narrow connection to a larger landmass.

Less common, but possible:

* Atoll: A ring-shaped coral reef that encloses a lagoon.

* Sandbar: A narrow strip of sand that rises above the water, sometimes forming a temporary island.

* Delta: A piece of land formed at the mouth of a river, usually surrounded by water but connected to the mainland.

* Marsh: A wetland area that is often flooded with water and has a high concentration of grasses.

To give a more precise answer, I need more context! What type of land are you thinking about?