December 3, 2012 - Colourful crater lakes of Kelimutu volcano, Flores Island, Indonesia. Tiwu Nua Muri Kofah (Lake of Young Men and Maidens) and Tiwu Ata Polo (Bewitched Lake). The two lakes are highly acidic due to underwater fumarole activity and are turqoise in colour.

December 3, 2012 - Colourful crater lakes of Kelimutu volcano, Flores Island, Indonesia. A crater wall separates Tiwu Nua Muri Koo Fai (Lake of Young Men and Maidens) and Tiwu Ata Polo (Bewitched Lake). The two lakes are highly acidic due to underwater fumarole activity and are turqoise in colour.

December 3, 2012 - Colourful crater lakes of Kelimutu volcano, Flores Island, Indonesia. Tiwu Nua Muri Koo Fai (Lake of Young Men and Maidens) and Tiwu Ata Polo (Bewitched Lake). The two lakes are highly acidic due to underwater fumarole activity and are turqoise in colour.

Very remote Shag Rocks, near South Georgia Island in the Scotia Sea, South Atlantic Ocean

Underwater view of the reef along the circumference of the Great Blue Hole on Lighthouse Reef, UNESCO, Belize

Aerial view of Balos Lagoon, Balos Beach and Cape Tigani, Gramvousa Peninsula, Chania Region, Crete, Greek Islands, Greece, Europe