by kevin mcneal on Flickr.The Deep Blue Hole – Yellowstone National Park, USA.
Entrance of St Beatus Caves, Interlaken, Switzerland
Walking on the river, Yangshuo, China
Ik Kil Cenote in Yucatan Peninsula, Mexico
by Ken Bondy on Flickr.Blue whale, Loreto, Baja California Sur, Mexico.
The beautiful library of Wiblingen Abbey in Ulm, Germany