Star trails form over the Memorial House of the Bulgarian Communist Party on mount Buzludzha in this long exposure picture taken on September 12, 2014. The monument was officially opened in 1981 by the Bulgarian Communist regime to mark 100 years of the set up of an organised Socialist movement, a predecessor of the Bulgarian Communist Party. The monument, no longer maintained by the Bulgarian government after the fall of the Communist regime in 1989, is now abandoned and vandalized. (Photo by Stoyan Nenov/Reuters)

Graffiti is sprayed near the main entrance of the Memorial House of the Bulgarian Communist Party on mount Buzludzha September 12, 2014. The writing reads: “Workers – men and women, from all countries, unite! Ahead! Comrades, let's bravely build up our great cause! Let's work, let us create - the worker we need to enlighten!”. (Photo by Stoyan Nenov/Reuters)

Power-generating windmill turbines are seen through the windows of the Memorial House of the Bulgarian Communist Party on mount Buzludzha September 12, 2014. (Photo by Stoyan Nenov/Reuters)

Photographers take pictures inside the crumbling main hall of the Memorial House of the Bulgarian Communist Party on mount Buzludzha September 12, 2014. (Photo by Stoyan Nenov/Reuters)

A monument is seen near the Memorial House of the Bulgarian Communist Party on mount Buzludzha September 12, 2014. (Photo by Stoyan Nenov/Reuters)

A man walks near the Memorial House of the Bulgarian Communist Party on mount Buzludzha September 12, 2014. (Photo by Stoyan Nenov/Reuters)

A photographer takes pictures inside the crumbling main hall of the Memorial House of the Bulgarian Communist Party on mount Buzludzha September 12, 2014. (Photo by Stoyan Nenov/Reuters)

A view of the Memorial House of the Bulgarian Communist Party on mount Buzludzha September 12, 2014. (Photo by Stoyan Nenov/Reuters)

Horses are seen near the Memorial House of the Bulgarian Communist Party on mount Buzludzha September 12, 2014. (Photo by Stoyan Nenov/Reuters)

Murals and graffiti are pictured inside the crumbling main hall of the Memorial House of the Bulgarian Communist Party on mount Buzludzha September 12, 2014. (Photo by Stoyan Nenov/Reuters)

Murals of (L-R) Karl Marx, Friedrich Engels and Vladimir Lenin are seen inside the crumbling main hall of the Memorial House of the Bulgarian Communist Party on mount Buzludzha September 12, 2014. (Photo by Stoyan Nenov/Reuters)

A view of the Memorial House of the Bulgarian Communist Party on mount Buzludzha September 12, 2014. (Photo by Stoyan Nenov/Reuters)

A view of the ceiling of the crumbling main hall of the Memorial House of the Bulgarian Communist Party on mount Buzludzha September 12, 2014. The text reads “Proletarians of all countries, unite!”. (Photo by Stoyan Nenov/Reuters)

A general view shows the crumbling main hall of the Memorial House of the Bulgarian Communist Party on mount Buzludzha September 12, 2014. (Photo by Stoyan Nenov/Reuters)