The Brutalist architectural style was popular in the mid-twentieth century. Any time you see a giant, cement building with a thick, angular silhouette — you can thank Brutalism. You may not find the style beautiful, but you have to admit these examples of it would make great scifi environments.
J. Edgar Hoover Building, the headquarters of the FBI, Washington D. C. (Charles F. Murphy and Associates, 1965-1975)
The Tetris-like building was built for the 1967 World's Fair. It has 146 residences, (354 concrete forms in 12 storeys) all of them with a private terrace.
(via Wikimedia Commons)
The John P. Robarts Research Library, University of Toronto (Mathers & Haldenby Architects with Warner, Burns, Toan & Lunde, 1968-1973)
Biblioteca Nacional, Buenos Aires, Argentina (Clorindo Testa, designed in 1961, constructed between 1971 and 1992)
Klinikum Aachen or Universitätsklinikum Aachen, the biggest single-building hospital in Europe (construction started in 1972, opened in 1985)
Central Research Institute of Robotics and Technical Cybernetics, St. Petersburg, Russia (1973-1988)
You can see more strange buildings of the Eastern Bloc from the last decades of communism here.
Wotruba Church or The Kirche Zur Heiligsten Dreifaltigkeit, Vienna, Austria (modelled by Fritz Wotruba, 1974-1978)
The third-largest tower in Eastern Europe. It has a two-story bridge between the two towers and a restaurant at the top.
(via Blago Tebi)