Watch out where you step at!

http://www.gather.com/viewArticle.action?articleId=281474978270077

 

http://www.ksee24.com/news/local/95289379.html

 

That second one almost looks like it had been bored into the ground.

 

Just been reading wiki's sinkhole page check this out.

http://upload.wikimedia.org/wikipedia/commons/6/61/Great_Blue_Hole.jpg

Kinda spooky how round,sheer and deep the drop is that's called the great blue hole in Belize its 400 feet deep,looks kinda dangerous driving a boat over it but its only water.

They look like an alien weapon in star trek has blasted a hole in the planet to me.

http://en.wikipedia.org/wiki/Sinkhole