Across
1
Region between the two tropic lines
3
Largest river in South America
4
Mountain that can erupt with lava
5
Deep narrow valley with steep sides
7
Tool for finding directions
8
Line dividing two countries
12
Flat grassland in tropical regions
Down
2
Wearing away of land by water or wind
3
Region surrounding the North Pole
6
City that is seat of government
9
Cold treeless Arctic plain
10
Half of the Earth
11
Largest hot desert in the world