Aerial view of CRH bullet trains setting out ahead of Spring Festival travel rush on January 31, 2018 in Hefei, Anhui Province of China. About 2.98 billion trips will be made during the 40-day Spring Festival travel rush. China will take multiple measures to ensure a smooth Spring Festival travel rush. (Photo by VCG/VCG via Getty Images)

Slovenian photographer Peter Gedei started caving 25 years ago and has carried a camera with him on every trip getting stunning pictures from his travels, capturing the ice formations, tight chambers and beautiful halls. Photo: The Ice Cave in Postojna, Slovenia. (Photo by Peter Gedei/Caters News)

These are the spectacular snaps of swirling star trails which transform the night sky into a kaleidoscope of color. Keen photographer Evgeniy Zaytsev, 24, captured the stunning shots on trips to Crimea, Altai and Murom, Russia. The pictures of circular star trails are formed by merging multiple photos taken over the course of several hours. Movement of the Earth causes the stars appear in different places in each image. Here: vibrate, colorful star trails over an abandoned beach house. (Photo by Evgeniy Zaytsev/Caters News)

Divers swim beside millions of silverside fish at Devil's Grotto, Cayman Islands. Swimming in unison, millions of silverside fish dwarf the divers. The fish create waves of silver light as they move around the grottos that lie beneath the surface of the Caribbean Sea. These amazing photographs were captured by Belgian photographer Ellen Cuylaerts, 44, on a diving trip to the Devil's Grotto, Cayman Islands. (Photo by Ellen Cuylaerts/This is Guavo Media)

In this June 17, 2014 photo, a North Korean man takes shelter in the rain next to long propaganda billboards in the town of Samjiyon in North Korea's Ryanggang province. The Associated Press was granted to embark on a weeklong road trip across North Korea to the country’s spiritual summit Mount Paektu. The trip was on North Korea's terms. An AP reporter and photographer couldn't interview ordinary people or wander off course, and government “minders” accompanied them the entire way. (Photo by David Guttenfelder/AP Photo)

Take a look at this stunning photo of Tolbachik, an active volcanic complex on the Kamchatka Peninsula in far eastern Russia. Lava fountains and rivers ran through the area for months after the eruption began with the opening of two Tolbachik fissures in November of 2012. In the midst of this activity, photographers Luda and Andrey (lusika33) took a trip down to see that stunning hell valley on earth. (Photo by lusika33)

“Touring the Koko-en Gardens adjacent to the Himeji castle was an unexpected highlight of our visit”, wrote Jeff Solar, 64, of Silver Spring, Md., about his trip to Japan. “The fall colors were outstanding and the gardens were both amazing and a bargain (just a few Yen added to the cost of the Himeji Castle admission)”. (Photo by Jeff Solar/2017 Washington Post Travel Photo Contest)

Mateo Santiago, Field Manager at Tropical Bamboo Nursery and Gardens, photographs rain water collecting in the corpse flower as Garden Manager Melanie Benson steadies a ladder. Santiago crinkled his nose up distastefully when he described its odor, which was at its worse Sunday night. “It smelled like a dead rat”. (Photo by Melanie Bell/Palm Beach Daily News)