What is it?
It's a bridge
What is it?
It's a lighthouse
What is it?
It's a canal
What is it?
It's a stream/a brook/a creek
What is it?
It's an estuary
What is it?
It's a strait
What is it?
It's a hill
What is it?
It's a swamp
What is it?
It's a pond
What is it?
It's a natural spring
