National Geographic's annual travel photography competition has kicked off, and is open for entries until 27 May 2016. Photographers can submit entries in any or all of three categories: Nature, People and Cities. The grand prize award winner will receive a seven-day polar bear photo safari for two at Churchill Wild–Seal River Heritage Lodge in Canada.

IBTimes UK presents a selection of photos submitted in the Nature category. See more – and enter your own pictures – on the National Geographic website.

National Geographic Travel Photographer of the Year Contest
Beast, by James Smart. Location: Blackhawk, South Dakota, United States. "Amazing supercell produces over the town of Blackhawk, South Dakota5. Flash flooding occurred near Rapid City."James Smart / National Geographic Travel Photographer of the Year Contest
National Geographic Travel Photographer of the Year Contest
Mystic shed, by Pierre Destribats. Location: Lapland, Finland. "A cold night on the top of this hill in Lapland, near the Russian border waiting for the dancing lights in the sky. All around, snow ghost are watching, standstill."Pierre Destribats / National Geographic Travel Photographer of the Year Contest
National Geographic Travel Photographer of the Year Contest
On Guard, by Reynold Dewantara. Location: Probolinggo, East Java, Indonesia. "This picture was taken during Mt Bromo's eruption. The horse seems a little agitated due to the sound of the eruption."Reynold Dewantara / National Geographic Travel Photographer of the Year Contest
National Geographic Travel Photographer of the Year Contest
The Snow Tree, by Yvonne Baur. Location: Bryce Canyon, Utah, United States. "During a snow storm I decided to head over to Bryce Canyon National Park and enjoy the freshly fallen snow. Visibility was down to almost zero, but then I found this single tree right next to a snow drift and knew this would be my shot."Yvonne Baur / National Geographic Travel Photographer of the Year Contest
National Geographic Travel Photographer of the Year Contest
The Wave, by Kenji Yamamura. Location: Utah. "Long drive and long hike but it was truly worth to see this scenery. The shutter sound was echoing around. It was my pleasure to frame this moment."Kenji Yamamura / National Geographic Travel Photographer of the Year Contest
National Geographic Travel Photographer of the Year Contest
Star Dune, by Johannes Öhl. Location: Death Valley, California. "This photo was shot shortly after sunrise at mesquite dunes. George Lucas chose this location for some scenes of Star Wars. The blue background is not the sky. These are mountains in the distance."Johannes Öhl / National Geographic Travel Photographer of the Year Contest
National Geographic Travel Photographer of the Year Contest
Powered sight, by Christoph Schaarschmidt. Location: Yulara, Northern Territory, Australia. "I had heard a lot about how beautiful Uluru could look when it rains. But I never believed that I would see it with my own eyes because the red centre of Australia is a very arid area. That's one of the reasons why Uluru is such a special place for the Anangu - the local aboriginal clan. If it rains, the water fills up the reservoirs around the rock, the only water source for several kilometres. This makes the Uluru Kata Tjuta National Park to special place for lots of rare animals as well."Christoph Schaarschmidt / National Geographic Travel Photographer of the Year Contest
National Geographic Travel Photographer of the Year Contest
Namibian Desert, by Doris Landertinger. Location: Swakopmund, Erongo, Namibia. "Springbok in front of a dune in the Namib desert."Doris Landertinger. / National Geographic Travel Photographer of the Year Contest
National Geographic Travel Photographer of the Year Contest
Trollstigen, by Christoph Schaarschmidt. Location: Bø, More og Romsdal, Norway. "I took this photo at Trollstigen in Norway. Standing there alone in the fog, I was waiting for the view to become clear. And then it happened, the fog disappeared and though it was 1am already, a car came slowly up the steep serpentines. It was my dream for a long time to take a photo of light trails like this in Norway - and it was just an awesome feeling that it worked out on the most beautiful and famous road. A few minutes later the fog returned, even thicker than before."Christoph Schaarschmidt / National Geographic Travel Photographer of the Year Contest
National Geographic Travel Photographer of the Year Contest
La Fournaise volcano, by Gaby Barathieu. Location: Saint-Denis, Reunion, Reunion.Gaby Barathieu / National Geographic Travel Photographer of the Year Contest
National Geographic Travel Photographer of the Year Contest
Moment of Impact, by Jaco Marx. Location: the Kgalagadi Transfrontier Park, South Africa. "I photographed the lions with back-light to have the dust illuminated and show the action in this scene. The lions were actually play-fighting and gave some opportunity to photograph interaction."Jaco Marx / National Geographic Travel Photographer of the Year Contest
National Geographic Travel Photographer of the Year Contest
Fascination, by Katsuyoshi Nakahara. Location: Minobu, Yamanashi, Japan. "Cherry blossoms like a Japanese painting. The smoke of the bonfire of old paper charms has brought a fantastic effect."Katsuyoshi Nakahara / National Geographic Travel Photographer of the Year Contest
National Geographic Travel Photographer of the Year Contest
The Spaceship, by Massimo Rumi. Location: Antarctica . "Last December i sailed to Antarctica on a 54-feet long-haul steel vessel. As we entered the Polar Zone this was one of the first icebergs we saw. Sculpted by the wind and waves, majestic in scale and with a dazzling white colour with layers of deep blue. The sun made a quick appearance through a hole in the clouds, just in time for this shot."Massimo Rumi / National Geographic Travel Photographer of the Year Contest
National Geographic Travel Photographer of the Year Contest
Terraces Village in the Mist, by Thierry Bornier. Location: Guizhou, China. "Captured this image early morning after waiting for a week until I got the right mood of light and fog."Thierry Bornier / National Geographic Travel Photographer of the Year Contest
National Geographic Travel Photographer of the Year Contest
Balanced Rock, by Manish Mamtani. Location: Moab, Utah. "Balanced rock and lone tree in Arches National Park"Manish Mamtani / National Geographic Travel Photographer of the Year Contest