My second card from Wroclaw and a new UNESCO card :)
This here is the Century Hall (later its name was changed into People's Hall, nowadays both names are used). It's not very old, built in 1912-14, but it influenced many other modern concrete buildings so thats why it has been a UNESCO whs since 2006.
I like it when the sender writes something about the card, so apart from some googled info, i can include that as well
It was erected by the architect Max Berg as a multi-purpose recreational building, situated in the Exhibition Grounds. In form it is a symmetrical quatrefoil with a vast circular central space that can seat some 6,000 persons. The 23m-high dome is topped with a lantern in steel and glass. It is a pioneering work of modern engineering and architecture.