Crater lakes appear when a caldera, a cauldron-like crater formed by the collapse of land following a volcanic eruption, becomes filled with water. Featured above are some of the most stunning, naturally formed crater lakes around the world.
Crater Lake (Okama), Mount Zao, Honshu, Japan
Kelimutu Crater Lake, Flores Island, Indonesia
Crater Lake, Mount Ruapehu, New Zealand
Crater Lake, Mount Pinabuto, Luzon, Philippines
Quilotoa Crater Lake, Ecuador
Vulcan Point within Crater Lake, Taal Volcano, Luzon, Philippines
Via Flickr: US Marine Corps (USMC) Marines with 81mm Mortar Platoon, 2nd Battalion (BN), 4th Marine Regiment (MAR REGT), attached to the 31st Marine Expeditionary Unit (MEU), fire an 81mm M252 mortar tube during a live fire training exercise .
Japanese Buddhists monks at the Sensō-ji temple in Asakusa district wear gas masks during training against future aerial attacks as Japan prepares for the Second Sino-Japanese War. Tokyo, Kantō region, Honshu, Japan. 30 May 1936.