Narodno Sabranie Square, Sofia
Ploshtad 'Narodno sabranie' (National Assembly Square) is a very good starting point as there are many beautiful buildnigs, museums, churches and other places of interest around. At the square you can see the Parliament (National Assembly), The Bulgarian Academy of Science and the monument of the Russian Tzar Nikolai the Liberator. The monument is by Italian sculptor Arnoldo Zocchi, who also designed the Liberty statue in Ruse, the Columbus monument in Buenos Aires, the Garibaldi monument in Bologna and others. Right behind the parliament you can see Bulgaria’s most famous cathedral, Alexander Nevski. Towards the end of Tzar Osvoboditel Blvd. you can see Bulgaria’s oldest university, St. Kliment Ohridski. If you follow the boulevard in the other direction, you can see the Natural History Museum, the Russian Church, the National Galery. From there you can easily reach the National Theatre, the Presidency, churches, museums and other landmarks.
Narodno Sabranie, central building and nice. I don't know the importance but for me is known as the building in which left side way you can go out from Sofia to north, just straight on.