Buzludzha Bulgarian Communist Monument 

Buzludzha Monument, was built on Buzludzha Peak in central Bulgaria by the Bulgarian communist government and inaugurated in 1981.
Construction of the monument began on 23 January 1974 under architect Georgi Stoilov, a former mayor of Sofia and co-founder of the Union of Architects in Bulgaria.[1] The peak was leveled into a stable foundation using TNT, reducing the mountain's height from 1,441 metres (4,728 feet) to 1,432 metres (4,698 feet).