Hosting an International Expo in 1911, Flaminio prove itself to be a cultural and recreational district, with the subsequent construction of a racecourse (closed in 1929) and of the Galleria Nazionale d'Arte Moderna.

During the I World War, the industrial area was reconverted for military purposes: the big Società Automobili Roma plant became a weapon factory, the Reale Fabbrica di Armi, and many little constructions, with a simple and linear architecture, were built to host barracks and laboratories.

When the construction works for the new auditorium began in 1994, Flaminio and the adjacent quartiere Parioli experienced an urban renewal process that lasted more than a decade, leading to the creation of MAXXI in 2010 and to the inauguration of the new Ponte della Musica-Armando Trovajoli in 2011.

Southward, Flaminio is delimited by the Aurelian Walls (alongside Via Luisa di Savoia), that separates it from Rione Campo Marzio (R. IV).

In the southern area, toponyms mostly commemorate jurists and philosophers, e.g. Domenico Alberto Azuni, Cesare Beccaria, Francesco Carrara, Cardinal De Luca, Gaetano Filangieri, Emanuele Gianturco, Giovanni Vincenzo Gravina, Matteo Renato Imbriani, Pasquale Stanislao Mancini, Enrico Pessina, Giuseppe Pisanelli, Gian Domenico Romagnosi, Giambattista Vico.