The link below is to an interesting article on streams that have been forced to flow underground. It is a very interesting read.
For more, visit:
http://environment.nationalgeographic.com/environment/photos/underground-rivers
The link below is to an interesting article on streams that have been forced to flow underground. It is a very interesting read.
For more, visit:
http://environment.nationalgeographic.com/environment/photos/underground-rivers