A never finished monument planned by the Communists to commemorate the Red Army's WW2 operations. Creepy and fascinating at the same time.
From this hill Soviet commander Rodion Malinovsky was coordinating the Red Army's operations at the end of the WW2. Since 1975 the Communist rule was working on building some kind of a memorial / monument for propaganda purposes.
First the actual bunker-like observatory was refurbished in the 70's and in mid 80's it was decided to build this rather monstrous monument.
The ground floor was supposed to house a small cinema together with a permanent exhibition, the metal structure above it was intended to be covered by glass panels and serve as an observatory and there was even an open-air soviet military museum planned.
The Velvet revolution in 1989 and the fall of the Communist regime put the construction to an end.
Wikipedia (Czech) https://cs.wikipedia.org/wiki/Pam%25C3%25A1tn%25C3%25ADk_Bratislavsko-brn%25C4%259Bnsk%25C3%25A9_operace
Address 69165, Czech Republic
Coordinates 48°59'47.937" N 16°43'51.668" E