Adventurer Sam Cossman movies towards the huge lava lake wearing a custom built industrial proximity heat suit on December 20, 2014 in Ambrym, Vanuatu. (Photo by Conor Toumarkine/Barcroft Media)

Haitians cross a collapsed bridge on the outskirts of Port-au-Prince, Haiti, March 24, 2016. The bridge collapsed as a truck was crossing it on March 18, according to local media. (Photo by Andres Martinez Casares/Reuters)

A girl dresses up as the Hindu deity Krishna to celebrate Janmashtami, his birthday in Agartala, India on August 26, 2019. (Photo by Abhisek Saha/Barcroft Media)

Weighing 1,500lb, Brutus the great white shark lunges at some bait off Guadalupe Island, Mexico in July 2022. (Photo by Euan Rannachan/Media Drum Images/The Times)

A baby orangutan called Barney shows off his dancing at Ragunan Zoo in Jakarta, Indonesia in the first decade of November 2023. (Photo by Syahrul Ramadan/Media Drum Images)

Police officers detain an opposition protester during a May Day rally in Saint Petersburg, Russia on May 1, 2019. Labor Day or May Day is observed all over the world on the first day of the month of May to celebrate the economic and social achievements of workers and fight for laborers rights. (Photo by Igor Russak/Reuters)

Revelers dance and shout as they listen to music, in front of the main stage, during the 21st Woodstock Festival in Kostrzyn-upon-Odra, Poland July 31, 2015. An estimated 200,000 people attended the ongoing festival, a brainchild of Polish journalist and social campaigner Jerzy Owsiak, on Friday. Owsiak initiated the event to say thank you to those who donated money to his GOCC charity organisation that delivers medical care for children. (Photo by Kacper Pempel/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 No longer maintained by the Bulgarian government, it has fallen into disuse.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.