Thyamis River near Ioannina, Greece (© Hercules Milas/Alamy)(Bing United States)

Aerial view of the International Fountain, Seattle, Washington (© Harald Sund/Getty Images)(Bing United States)

Rocca Guaita (First Tower), Republic of San Marino (© SIME/eStock Photo)(Bing United States)

Frying Pan Lake in the Waimangu Volcanic Rift Valley, New Zealand (© Uli Hamacher/Getty Images)(Bing United States)

California sea lions off Anacapa Island, Channel Islands National Park, California (© Ian Shive/Tandem Stock)(Bing United States)

Aerial view of Mount St. Helens, Washington (© Muralee Raghavan)(Bing United States)

Aerial view of Castello Maniace in Syracuse, Sicily, Italy (© Antonino Bartuccio/SIME/4Corners)(Bing United States)

Chrysanthemum flower, green "Anastasia" variety (© Tom Joslyn/age fotostock/SuperStock)(Bing United States)

Starling flock at dusk (© Martin Woike/Corbis)(Bing United States)

Visitors at the Empty Sky Memorial, Liberty State Park, Jersey City, New Jersey (© Aristide Economopoulos/The Star-Ledger)(Bing United States)

The sun peeks through Mesa Arch in Canyonlands National Park, Utah (© Zev Yanovich)(Bing United States)

Circular Pool in Dales Gorge, Karijini National Park, Australia (© Tomasz Makarewicz/360cities.net)(Bing United States)

Chand Baori stepwell in Abhaneri, India (© Tilak Haria/Getty Images)(Bing United States)

Sea cave and coral sand beach of South Iwo Jima Island (Minami-Iōtō), Japan (© ICHIRO/Getty Images)(Bing United States)

Orange corridor, San José del Cabo, Mexico (© Jeremy Woodhouse/Aurora Photos)(Bing United States)

Taipei, Taiwan, seen from Yangmingshan National Park (© Eason Lin Ladaga/Getty Images)(Bing United States)

Red fox, Chukotka region, Russia (© Ivan Kislov/In cooperation with 500px)(Bing United States)

Time-lapse exposure of the night sky above Bromo Tengger Semeru National Park in East Java, Indonesia (© Weerapong Chaipuck/In cooperation with 500px)(Bing United States)

Bridge over Sylvenstein Lake in Upper Bavaria, Germany (© Gavin Hellier/In cooperation with 500px)(Bing United States)

Magnificent tree frog in Drysdale River National Park, Australia (© Thomas Marent/Corbis)(Bing United States)

Pear orchard in Okanagan Valley, British Columbia, Canada (© Henry Georgi/Getty Images)(Bing United States)

Mount Shasta, California (© Nagesh Mahadev)(Bing United States)

Sandhill cranes flying over Bosque del Apache National Wildlife Refuge, New Mexico (© Patrick Frischknecht/Aurora Photos)(Bing United States)

Autumn foliage, Schoenbrunn Palace, Vienna, Austria (© Zoonar GmbH/Alamy)(Bing United States)

Marine City in the Haeundae district of Busan, South Korea (© Getty Images)(Bing United States)

California ground squirrels at Seal Rock on 17-Mile Drive on the Monterey Peninsula, California (© Eric Lovelin)(Bing United States)

Lava rock pools at the southern end of Lake Turkana, in Kenya (© Nigel Pavitt/Corbis)(Bing United States)

A goat on the castle rocks in Myrina, on the isle of Lemnos, Greece (© Ashley Cooper/Corbis)(Bing United States)

Balanced rocks in Guadalupe Mountains National Park, Texas (© Minden Pictures/SuperStock)(Bing United States)