This is an Icelandic waterfall called Litlanesfoss and the naturally occurring rock formation is columnar jointed basalt. (via Kotkke: Hexagonal rocks)
The Barrier (by Andy Grellmann)
(by Cody Cobb)
Rock Pool Sunset,Scotland (by PeterYoung1)
Loch Morlich After Sunset. by midlander1231 on Flickr.
untitled by coolhandluke on Flickr.
the world and us by Rona Keller on Flickr.
My Heart by jazure on Flickr.
Magic Creek by Peter Bowers on Flickr.