Rivers are always surrounded by higher land.
A Valley-------------------------No a valley is not surrounded by higher land, the correct answer is a "basin" or a "depression".
a valley
Basin
a basin
Mesopotamia means "land between two rivers".
Basin that is the answer
Basin that is the answer
Rivers in the peninsula(Peninsulas are land surrounded with water on three sides- Left, right, and down.)
A low area surrounded by higher land is called a basin. The areas are usually bowl shaped and are completely surrounded.
The Tigris and Euphrates Rivers both flooded in Mesopotamia (they surrounded it), bringing silt (fertile soil) to the land.
That depends on whether the land is surrounded by water or something else. If it is surrounded by water, it is an island. If it is surrounded by water but is sufficiently large, it may be called an island continent (an example is Australia). If it is a land area completely surrounded by high mountains, rivers will flow to the land that is surrounded instead of to the ocean in that area. That would make the land an endorrheic basin.
example of water surrounded by land is lake but not absolutely because there is a lake and other bodies of water like seas or oceans connected by rivers.