Gunung Leuser National Park is a national park covering 7,927 km² in northern Sumatra, Indonesia, straddling the border of North Sumatra and Aceh provinces. The national park, named after Mount Leuser (3,381 m), protects a wide range of ecosystems. An orangutan sanctuary of Bukit Lawang is located inside the park. Together with Bukit Barisan Selatan and Kerinci Seblat national parks it forms a World Heritage Site, Tropical Rainforest Heritage of Sumatra.

Aquarium visitors attend a dinner party in an underwater tunnel in Tianjin, China on September 15, 2016. Tianjin Haichang Polar Ocean World opened in the city of Tianjin, southeast of Beijing, in 2010. It gives visitors a chance to see more than 150 large animals from the Arctic and Antarctic regions, including polar bears. (Photo by Feature China/Barcroft Images)

A woman weeps after an announcement that Thailand's King Bhumibol Adulyadej has died, at the Siriraj hospital in Bangkok, Thailand, October 13, 2016. Thailand's Royal Palace says King Bhumibol, the world's longest-reigning monarch, has died at age 88. (Photo by Athit Perawongmetha/Reuters)

Dogs and their owners dressed in Halloween costumes parade during the annual Haute Dog Howl'oween event in Long Beach, California on October 30, 2016. The parade, which claims to be the largest Halloween dog event in the world, sees hundreds of dogs and their owners dressed in colorful costumes celebrating the festival. (Photo by Mark Ralston/AFP Photo)

A loved-up couple have captured the moments they shared a dip-kiss in different locations around the world. Rob, 34, and Joli Switzer, 33, from Maryland, embark on a minimum of four international holidays per year to ensure that they get their unique dip-kiss photograph. Here: Rob Switzer 34 proposed to Joli 33 whilst they were on holiday in Moscow, Russia. (Photo by Dipkiss Travels/Caters News Agency)

Daisuke Nagasawa, 49, has spent the past few years taking his two faithful cats, Daikichi and Fuku-Chan, around the world with him. Here: Daisuke Nagasawa travels nationally and internationally with his beautiful kitties Fuku-Chan and Daikichi. The two pose under the iconic Japanese cherry blossoms. (Photo by Daisuke Nagasawa/Caters News Agency)

Women wearing Dirndl, a traditional Alpine folk dress, run to get a place in a tent for the opening of the 185th Oktoberfest beer festival in Munich, Germany, 22 September 2018. The Oktoberfest lasts until October 7 and is the world's largest beer festival. The beer festival typically draws over six million visitors. (Photo by Karl- Josef Hildenbrand/DPA/Alamy Live News)