Palazzo della Civiltà Italiana

The Rationalist 'Square Colosseum' in the EUR district — a stark white cube of stacked arches built under Mussolini for a planned 1940s world's fair, its rows of identical openings a fascist-era homage to the real Colosseum across the city. Coldly symmetrical and instantly recognizable, it now serves as the headquarters of the fashion house Fendi. For visitors, it's a fascinating, unsettling monument — the clearest built statement of Rationalist architecture and its political moment, set in the purpose-built EUR quarter, where the regime's vision of a future Rome stands frozen and strangely beautiful.