Artists wearing Japanese traditional clown masks march during the First Konpira Festival at Kotohiragu shrine in Tokyo Wednesday, January 10, 2018. The shrine is dedicated to sailors and seafaring. (Photo by Eugene Hoshiko/AP Photo)

A Hong Kong Correctional Services Dog Unit (CSDU) officer demonstrates training at the CSDU training facility in Stanley, Hong Kong, China, 27 February 2018. The Hong Kong CSDU consists of 29 staff members divided across six dog teams. According to the department's latest figure from 2017, the average daily penal population of Hong Kong was 8,529. (Photo by Jérôme Favre/EPA/EFE)

A Great White Pelicans eats fish in the Mishmar HaSharon reservoir, Israel, Wednesday, November 4, 2015. Thousands of Pelicans stop in the reservoir for food provided by the Israeli nature reserves authority as they make their way to Africa. (Photo by Ariel Schalit/AP Photo)

A woman wearing a mask walk in a street in a Yonghegong Lama temple compound seen shrouded in smog in Beijing, China, 30 November 2015. Beijing issued an orange alert for heavy smog 30 November, the highest level this year. Authorities in the Chinese capital warned of 'severe pollution' and advised the capital's 20 million inhabitants to stay indoors. (Photo by How Hwee Young/EPA)

Participants of the 77th edition of the annual Christmas swimming 'Coupe de Noel' jump into the waters of Lake Geneva, in Geneva, Switzerland, 20 December 2015. More than 1,540 men and women braved the water temperature of just 8 degrees Celsius as they swam a 120 meters distance at the traditional Christmas swimming in Geneva. (Photo by Salvatore Di Nolfi/EPA)

Lowry Park Zoo elephants Matjeka, 23, and her 1-year-old daughter, Mavi, apply a liberal coating of “sunscreen” to themselves in a clay mud wallow at the park Tuesday, August 12, 2014, in Tampa, Fla., on the park's first observation of World Elephant Day to raise awareness of the wild African elephant crisis. “Elephants are prone to being sunburned”, said associate curator Chris Massaro. “What they need is lot of mud or clay to roll around in and cover up their skin so it will protect it from the sun”. (Photo by Cherie Diez/AP Photo/The Tampa Bay Times)

A sculptural artwork depicting former Chilean dictator Augusto Pinochet and headless presidents shot by a hooded high school student (not pictured) is seen at the Contemporary Art Museum in Santiago, December 2, 2014. The artwork, part of the “El ladrillo angular” (The angular brick) exhibition, portrays a student fighting against the ongoing continuity of dictatorship because of a political and economic system which has been impossible to destroy, according to “Papas Fritas” the artwork's creator. (Photo by Ivan Alvarado/Reuters)

Buzludzha is a historical peak in the Central Stara Planina, Bulgaria and is 1441 metres high. In 1868 it was the place of the final battle between Bulgarian rebels led by Hadji Dimitar and Stefan Karadzha and the Ottoman Empire. The Buzludzha Monument on the peak was built by the Bulgarian communist regime to commemorate the events in 1891 when the socialists led by Dimitar Blagoev assembled secretly in the area to form an organised socialist movement with the founding of the Bulgarian Social Democratic Party, a fore-runner of the Bulgarian Communist Party. The Monument was opened in 1981. No longer maintained by the Bulgarian government, it has fallen into disuse. Buzludzha is reached by a 12 km side road from the Shipka Pass.