1311-1322 - The cliff rim of Keyhole Sink in the Kaibab National Forest near Williams Arizona. This sink is an open ended sinkhole where water can flow out of it.

1311-1321 - The cliff rim of Keyhole Sink in the Kaibab National Forest near Williams Arizona. This sink is an open ended sinkhole where water can flow out of it.

1311-1320 - A still pond in Keyhole Sink in the Kaibab National Forest near Williams Arizona. This sink is an open ended sinkhole where water can flow out of it.

1311-1319 - The cliff wall of the Keyhole Sink in the Kaibab National Forest near Williams Arizona. This sink is an open ended sinkhole where water can flow out of it.

1311-1318 - The cliff wall of the Keyhole Sink in the Kaibab National Forest near Williams Arizona. This sink is an open ended sinkhole where water can flow out of it.

1382-3942 - Woman walking on cold lava flow on the coast named 'Le Grand Brule' on the Southeast part of Reunion island, Overseas departement of France, Indian Ocean

1382-3941 - Fern (nephrolepis abrupta) and boehmeria (boehmeria penduliflora) growing on pahohoe lava flow. The coast named 'Le Grand Brule' on the Southeast part of Reunion island,overseas departement of France,Indian Ocean

832-406505 - Wooden bridge and restaurant above radovna river flowing through vintgar gorge near bled, slovenia, during a sunny summer day

832-406502 - Tourists wearing helmets are enjoying a summer walk along the stunning turquoise radovna river flowing through the vintgar gorge near bled, slovenia

832-406499 - Mother carrying her son while observing stunning turquoise radovna river rapids flowing through vintgar gorge near bled, slovenia

832-406493 - Turquoise water flowing under wooden bridge over tolmin gorges in triglav national park, slovenia

832-406446 - Crystal clear water cascading from a small waterfall into lake dobbiaco, reflecting the majestic dolomite peaks under a summer sky

1387-1265 - October 16, 2013 - Nighttime eruption of Kliuchevskoi (Klyuchevskoy) Volcano, Kamchatka, Russia. Ash cloud and lava flow are produced by the activity of the snowcovered conical stratovolcano. Column of steam rises where lava flow is melting glacier.

1387-1264 - October 16, 2013 - Nighttime eruption of Kliuchevskoi (Klyuchevskoy) Volcano, Kamchatka, Russia. Ash cloud and lava flow are produced by the activity of the snowcovered conical stratovolcano.

1387-1263 - October 15, 2013 - Nighttime eruption of Kliuchevskoi (Klyuchevskoy) Volcano, Kamchatka, Russia. Ash cloud and lava flow are produced by the activity of the snowcovered conical stratovolcano. Column of steam rises where lava flow is melting glacier.

1387-1260 - October 16, 2013 - Eruption of Kliuchevskoi (Klyuchevskoy) Volcano, Kamchatka, Russia. Ash cloud and lava flow are produced by the volcano which is partially shrouded in cloud. Kamen volcano is seen on right.

1387-1259 - October 16, 2013 - Nighttime eruption of Kliuchevskoi (Klyuchevskoy) Volcano, Kamchatka, Russia. Ash cloud and lava flow are produced by the activity of the volcano which is partially shrouded in cloud. Kamen volcano is seen on right.

1387-1217 - December 23, 2007 - Lava flow on the flank of Pacaya volcano, Guatemala.

1387-1191 - Close-up of lava flow, Kilauea volcano, Big Island, Hawaii.

1387-1185 - November 2006 - Lava flow during eruption of Mount Etna volcano, Sicily, Italy.

1387-1183 - November 2006 - Boulder rolling in lava flow at dusk during eruption of Mount Etna volcano, Sicily, Italy.

1387-1182 - November 2006 - Lava flow at nightfall during eruption of Mount Etna volcano, Sicily, Italy.

1387-1180 - November 2006 - Lava flow during eruption of Mount Etna volcano, Sicily, Italy.

832-406242 - Wall of columnar basalt with waterfall Bridal Veil Falls, tropical vegetation, Pakoka River, Makomako, Waikato, North Island, New Zealand, Oceania

1382-3501 - Sosu, a bamboo water fountain at Eikan-do Zenrin-ji, head temple for the Seizan branch of Jodo-Shu (Pure Land) Buddhist sect, Kyoto, Japan

1311-1209 - The granite riverbed of the Agua Fria River Canyon in the Agua Fria National Monument of Arizona.

1311-1205 - The granite riverbed of the Agua Fria River Canyon in the Agua Fria National Monument of Arizona.

1311-1196 - The granite riverbed of the Agua Fria River Canyon in the Agua Fria National Monument of Arizona.

1202-1118 - Atlantic surf rolls across granite shoreline rocks, at Porthgwarra Cove, near Land's End, in the far west of Cornwall, Great Britain.

1358-671 - Cuckmere Haven in the South Downs National Park, East Sussex, England, UK, where the Cuckmere river flows into the English Channel. The chalk cliffs to the East are known as the Seven Sisters.

1365-1067 - Agua d'Alto waterfall, San Vicente, Madeira

1365-1049 - Roadside waterfall, central mountains, Madeira

1365-1038 - Agua d'Alto waterfall, San Vicente, Madeira

1365-1036 - Agua d'Alto waterfall, San Vicente, Madeira

844-40187 - View of Nile River from Aswan High Dam on a sunny day, Aswan, Egypt, Africa

1245-4756 - Waterfall at Moteipa Trail, Palenque Archaeological Site, Palenque, Chiapas State, Mexico

1245-4755 - Waterfall at Moteipa Trail, Palenque Archaeological Site, Palenque, Chiapas State, Mexico

1245-4734 - Waterfall at the Palenque Archaeological Site, Palenque, Chiapas State, Mexico

1245-4719 - Waterfall at the Palenque Archaeological Site, Palenque, Chiapas State, Mexico

1245-4718 - Roberto Barrios Waterfalls, Chiapas State, Mexico

1245-4717 - Roberto Barrios Waterfalls, Chiapas State, Mexico

1245-4715 - Misol Ha Waterfall, Chiapas State, Mexico

1245-4712 - Agua Azul Waterfalls, Arroyo Agua Azul, Chiapas State, Mexico

1390-281 - Three tiered waterfall (SanDieQuan) in Lushan (Mount Lu), Jiujiang City, Jiangxi, China. Lushan is a UNESCO World Heritage site, it is one of China's most famous mountains known for its natural beauty.

1382-3351 - Rickshaws in a street of Delhi, India, Asia

1311-1130 - A water leak from a crack in Stone Dam in the Kaibab National Forest, Arizona, USA

685-2968 - Freeway aerial view, United States of America

1382-3304 - Indus River, Leh district, Ladakh region, state of Jammu and Kashmir, India, Asia

1382-3264 - Indus River valley, Leh district, Ladakh region, state of Jammu and Kashmir, India, Asia

1382-3263 - Indus River valley, Leh district, Ladakh region, state of Jammu and Kashmir, India, Asia

1365-951 - Allt Dearg Mor and Cullin Hills from near Sligachan, Isle of Skye, Scotland

1365-950 - Allt Dearg Mor and Cullin Hills from near Sligachan, Isle of Skye, Scotland

1365-948 - Bride's Veil Falls, Isle of Skye, Scotland

1365-947 - Bride's Veil Falls, Isle of Skye, Scotland

1365-946 - Bride's Veil Falls, Isle of Skye, Scotland

1365-945 - Bride's Veil Falls, Isle of Skye, Scotland

1365-944 - Bride's Veil Falls, Isle of Skye, Scotland

1365-943 - Bride's Veil Falls, Isle of Skye, Scotland

1365-941 - Bride's Veil Falls, Isle of Skye, Scotland

1365-940 - Bride's Veil Falls, Isle of Skye, Scotland

1382-3154 - Small torrent flowing through a fern bed in the undergrowth, Nordmannvikdalen valley, region of Lyngen, County of Troms, Norway, Northern Europe

1382-3153 - Small torrent flowing through a fern bed in the undergrowth, Nordmannvikdalen valley, region of Lyngen, County of Troms, Norway, Northern Europe

1112-11976 - Photographer at Godafoss (Waterfall of the Gods), Iceland

1382-3066 - Kuang Si waterfalls, Luang Prabang, Laos

1382-3064 - Couple admiring the Kuang Si waterfalls, near Luang Prabang, Laos

1382-3063 - Man admiring the Kuang Si waterfalls, Luang Prabang, Laos

844-39876 - View of Gullfoss Waterfall on the Hvita River in winter, Western Region, Iceland

844-39875 - View of Gullfoss Waterfall on the Hvita River in winter, Western Region, Iceland

844-39874 - View of Gullfoss Waterfall on the Hvita River in winter, Western Region, Iceland

844-39872 - View of Gullfoss Waterfall on the Hvita River in winter, Western Region, Iceland

844-39869 - View of Gullfoss Waterfall on the Hvita River in winter, Western Region, Iceland

844-39867 - View of Gullfoss Waterfall on the Hvita River in winter, Western Region, Iceland

1112-11833 - A beautiful waterfall just outside the small Norwegian summer area in Sandvika Bay on the south side of Svesfjord, Norway

1112-11813 - Water melting from the Briksdalsbreen glacier south of the small town of Olden in coastal Norway, Vestland, Norway

1365-895 - Ice detail, River Etive, Rannoch Moor, Highland, Scotland, United Kingdom

1365-889 - Buachaille Etive Mor, Rannoch Moor, Highland, Scotland, United Kingdom

1365-881 - Lodore Falls waterfalls, Borrowdale Valley, Lake District National Park, UNESCO, Cumbria, England, United Kingdom

1365-880 - Lodore Falls waterfalls, Borrowdale Valley, Lake District National Park, UNESCO, Cumbria, England, United Kingdom

1365-878 - Lodore Waterfalls, Borrowdale Valley, Lake District National Park, UNESCO, Cumbria, England, United Kingdom

1112-11797 - Slow motion exposure of a stream around the small town of Hellemobotn, Tysfjord, Nordland, Norway

1112-11588 - Glacial iceberg detail from ice calved off the Sawyer Glacier in Tracy Arm, Southeast Alaska, United States of America

1390-101 - Stone bridge over a river in picturesque 1000 year old Guodong Ancient Village, Wuyi County, Jinhua City, Zhejiang Province, China

1353-800 - Waterfall from Slate Cavern Tunnel entrance, Dinorwig Quarry (Dinorwic Quarry), Eryri (Snowdonia National Park), North Wales, United Kingdom

1372-985 - Cascading waterfall beneath a vivid red bridge, surrounded by moss-covered rocks and lush greenery in a peaceful forest, Kyoto, Honshu, Japan

1265-856 - Dubai skyline at dusk with Burj Khalifa, the world tallest building and Sheikh Zayed road traffic, Dubai, United Arab Emirates

1265-854 - Traffic on a busy intersection on Sheikh Zayed highway, Dubai, United Arab Emirates

1265-817 - Night traffic on a busy intersection on Sheikh Zayed highway, Dubai, United Arab Emirates

1265-814 - Traffic on a busy intersection on Sheikh Zayed highway, Dubai, United Arab Emirates

1365-823 - Ribera dos Caldeiroes waterfalls, near Achada, Sao Miguel, Azores Islands, Atlantic, Portugal

1365-822 - Ribera dos Caldeiroes waterfalls, near Achada, Sao Miguel, Azores Islands, Atlantic, Portugal

1365-821 - Ribera dos Caldeiroes waterfalls, near Achada, Sao Miguel, Azores Islands, Atlantic, Portugal

1365-820 - Ribera dos Caldeiroes waterfalls, near Achada, Sao Miguel, Azores Islands, Atlantic, Portugal

1365-818 - Ribera dos Caldeiroes waterfalls, near Achada, Sao Miguel, Azores Islands, Atlantic, Portugal

1292-5277 - Foncalada's Fountain, UNESCO, Oviedo, Asturias, Spain

1382-2237 - Bathers in irrigation canal, Birkat Al Mouz, Al Dakhliya region, Falaj irrigation system (Falaj Al-Khatmeen), UNESCO, Oman, Arabian Peninsula

1382-2234 - Irrigation canal in palm grove. Birkat Al Mouz, Al Dakhliya region, Falaj irrigation system (Falaj Al-Khatmeen), UNESCO, Oman, Arabian Peninsula

844-37755 - View of Kyoto Station interior during day, Shimogyo Ward, Higashishiokoji Kamadonocho, Kyoto, Honshu, Japan

1382-2128 - Mountain stream through a spruce forest, South Tyrol (Alto Adige), Italy

1382-2049 - Young woman by the torrent, Riva Valley (Val di Riva) (Reintal), near Ahrntal (Valle Aurina), South Tyrol (Alto Adige), Italy

1382-2022 - Reno di Medels river, Val Piora, Canton Ticino, Switzerland