A worker stands under the Airlander 10 hybrid airship during its unveiling in Cardington, Britain March 21, 2016. The world's largest aircraft has been unveiled for the first time since being fully assembled in the UK. The 302ft (92m) long Airlander 10 – part plane, part airship – was floated in a First World War hangar in Bedfordshire. (Photo by Darren Staples/Reuters)

A student shouts slogans against Venezuelan President Nicola Maduro during a protest on the main highway in Caracas on March 30, 2017. Venezuela' s Supreme Court took over legislative powers Wednesday from the opposition- majority National Assembly, whose speaker accused leftist President Nicolas Maduro of staging a “coup”. (Photo by Juan Barreto/AFP Photo)

Supporters of Pakistan Tehreek-e-Insaf (PTI) party of Prime Minister Imran Khan shout slogans outside the Parliament House building in Islamabad on April 3, 2022. Pakistan will go to the polls to elect a new government within three months after Prime Minister Imran Khan foiled an attempt to boot him from office April 3 by getting the president to dissolve the national assembly. (Photo by Aamir Qureshi/AFP Photo)

A gopher tortoise walks the grounds of NASA's Kennedy Space Center in Florida, near the Vehicle Assembly Building on January 18, 2024. An all-European crew including Turkey's first astronaut are poised to blast off to the International Space Station in a mission with Axiom Space, as countries hungry for a taste of space turn increasingly to the private sector. (Photo by Chandan Khanna/AFP Photo)

An air raid drill at Seattle College caught students William Bates, left, and Edna Mae Farrell, right, while they were eating their lunch in the school café, but they simply took shelter under the table and continued eating in Seattle, Washington, March 17, 1942. Air raid wardens said 350 students left their classrooms and assembled in shelters within one minute in first at the college. (Photo by AP Photo)

Young people play with foam during a march to commemorate Youth Day in Caracas, Venezuela, 12 February 2025. The president of Venezuela's National Assembly (AN, Parliament), Chavista Jorge Rodriguez, invited, before hundreds of followers who commemorated Youth Day, all young migrants to return to the country so that they can “build a prosperous homeland”. (Photo by Ronald Pena R./EPA)

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.