All the visible areas of an area of land

(a)  

The adjectives you can use to describe me would be dry, arid,

vast, sweltering, and sandy.

(a)  

I am the spreading of a river into smaller channels as it meets the sea. I am shaped like a triangle. Sort of.

(a)  

You can find me in the side of a cliff or hill. I've probably got bats inside. Or yesterday's homework.

(a)  

I'm a bigger version of a cave, often with large connected chambers.

(a)  

An area of low land between mountains or hills. Perfect place for a town?

(a)  

A green area in an otherwise dry desert. Water comes from deep below.

(a)  

A long narrow mountain or hill top. Perfect for walking your mountain goat.

(a)  

A deep gorge (narrow valley) with usually with a river flowing through it

(a)