They're not the work of World War II bombs or aliens or fairies. Instead, mysterious underwater rings spotted off the coast of Denmark are the result of poison.
Agadir Canyon is roughly the size of the Grand Canyon, and was carved out by flows of sediment from landslides off the coast of northwest Africa.
Underwater photographer Jason Isley of Scubazoo.com, based in South East Asia, found a creative way to document marine creatures using figurines.
A crazy design proposal for an underwater city can't be kept down.