Across
1
Low-lying land surrounded by higher ground
4
Largest river in South America
5
Large slow-moving mass of ice
6
Distance east or west of prime meridian
11
Area where water covers the soil
12
Seasonal heavy rainfall
Down
2
Largest hot desert in the world
3
Deep narrow valley with steep sides
7
City that is seat of government
8
Imaginary line around the middle of Earth
9
Land surrounded by water on three sides
10
Flat elevated area of land