Currently found only this article with “maybe” address:
Lachezar Stanchev Street in the Izgrev borough
And from comments found news about that opening date is September, 16.
This official news also says that this address is right:
Some of the National Art Gallery’s works are to go on travelling exhibitions, while some will go on temporary loan to the new Museum of Socialist Art, on Lachezar Stanchev Street in the Izgrev borough, near the Sofia office of the traffic police.
And this news finally get the right address:
7 Lachezar Stanchev Str (ул. Лъчезар Станчев 7)
(Google map, wrong street title, but from here location is right)
Credit:stackoverflow.com‘
4 Mar, 2024
5 Mar, 2024
4 Mar, 2024