American socialite and media personality Kim Kardashian sweats out her stress in a sauna in the second decade of January 2023. (Photo by kimkardashian/Instagram)

Scientists have captured these images in laboratories during research into what makes our daily food. Photo: Blueberry. (Photo by SPL/Barcroft Media)

The pugs dressed in Parka jackets in Sonoma County, California. (Photo by Phillip Lauer/Barcroft Media)

An x-ray of a woman drinking, taken by British artist and photographer Hugh Turvey in London, England. (Photo by Hugh Turvey/SPL/Barcroft Media)

This bat gives a cheeky smile as he gobbles down his food at Singapore Zoo, on September 10, 2013. (Photo by Benny Iskander/HotSpot Media)

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)

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 No longer maintained by the Bulgarian government, it has fallen into disuse.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.