Across
1
Line dividing two countries
4
Deep narrow valley with steep sides
5
Body of water surrounded by land
6
Low-lying land surrounded by higher ground
9
Half of the Earth
11
Largest ocean on Earth
12
Land surrounded by water
Down
2
Ridge of rock or coral near the surface
3
Height above sea level
7
Large natural stream of water
8
Narrow sea inlet between cliffs
10
Seasonal heavy rainfall