16 million leva were collected, as both voluntary and obligatory donations, of which 14,186,000 were spent on the monument. The rest was spent on the construction of three kindergartens. It took military construction units almost seven years to complete, and more than 6000 workers and experts took part in the construction. Over 20 leading Bulgarian artists worked for 18 months in order to complete the interior decoration, and verses of "The International" and "The Worker's March" were inscribed on the entrance of of the memorial.
The interior was partially clad in marble and the staircases were decorated with red cathedral glass. In the 15 meter-high main hall a 500 sq.m. fresco was constructed, which included portraits of Marx, Engels, Lenin and Todor Zhivkov (the leader of the People's Republic of Bulgaria from 1954 to 1989). The dome of the structure was covered with thirty tonnes of copper and two 12m stars of ruby glass were built into the top of the 70m high tower. These were made in the Soviet Union, and were three times bigger than those in the Kremlin.
The monument was inaugurated by Todor Zhivkov in 1981.
On 10th of November 1989 Zhivkov stepped down after 35 years in power, the day after the fall of the Berlin Wall. Immediately afterwards the Politburo ordered the removal of his portrait from the memorial. In 1991 the monument was ceded to the state, abandoned, looted and left to rot.
This is a shot of the outer ring of the main structure.