Casa del Fascio, Rationalist palace in Trieste, Italy.

Casa del Fascio is a palace in central Trieste built according to rationalist design principles with geometric facades and clean lines. The structure uses light-colored local limestone and displays the characteristic emphasis on functional design and mathematical proportions.

In 1934 mayor Enrico Paolo Salem held a competition for a Casa del Fascio, won by Raffaello Battigelli and Ferruccio Spangaro over Umberto Nordio. Benito Mussolini laid the foundation stone in 1938, but work ran from 1940 to 1942. From 1945 to 1954 the Allied Military Government used the building, then it became Trieste's Questura.

The building was repurposed after the war and now serves completely different functions than its original intent. Its clean facade with geometric forms shows principles that visitors can observe in the stone surfaces and window arrangement.

The building is located near the city center of Trieste and is easy to explore from the outside. Visitors should note that it is an active administrative building, so interior access may be limited.

The four corner towers with their wide openings are probably a nod to the quadriburgium, the fortified outposts that marked the Roman Empire's frontier. The facade facing the Roman theatre is curved, echoing the shape of the ancient auditorium beside it.