The National Palace of Culture (also known as the NDK) is perhaps the most famous and recognizable building in Sofia. It is the cultural center of the capital, where conferences, exhibitions, and special events are regularly held. The building is also the largest congress center in Southeastern Europe. The main purpose of the building, which has 13 rooms and is located in the center of Sofia, is to be used for cultural events. So it is a good idea to check in advance what upcoming events are organized there so that you can fully enjoy the rich cultural atmosphere around the palace. 

The largest hall in the National Palace of Culture (Hall 1) has 3380 seats. The hall was used by some of the greatest Bulgarian and world performers. The Palace hosts an average of over 300 events annually, including international congresses, political forums, business conferences, music and film festivals, concerts, dance performances, theater productions, and exhibitions.  

In the halls of the National Palace of Culture were the Bolshoi Theater, Swedish Royal Ballet, English Royal Ballet, Lili Ivanova, Andrea Bocelli, Goran Bregovic, James Brown, and many others. 

The building is located on 123,000 m² of land, has over 8 floors and 3 underground levels. In front of the National Palace of Culture, there are green areas with beautiful flowers and a complex of fountains. Close to the building, there are many shopping complexes and hotels. 

Some of the nearby landmarks around the National Palace of Culture are: 

South Park 

Garden "Banya Lozenets" 

Army sports school CHAVDAR Sofia 

National Museum "Earth and Man" 

"Holy Seventh-day" temple 

Bukata Garden 

Garden "St. George" 

Ivan Lazarov House-Museum 

Since the National Palace of Culture is one of the most visited places in Sofia, plenty of shops, pubs and cafés can be seen around it. 

The foundations of the National Palace of Culture were laid in 1978. Its opening was in 1981 as part of the initiatives to celebrate 1300 years since the establishment of the Bulgarian country. The idea of creating the building with cultural function is of Lyudmila Zhivkova. Even the name of the National Palace of Culture until 1990 is the National Palace of Culture "Lyudmila Zhivkova". 

Sources: 

https://bg.wikipedia.org/wiki/Национален_дворец_на_културата 

http://www.ndk.bg/за-нас