Originally, the site of the villa was much larger than it is today, including what is now Villa Mirafiori and Villa Crespi.
The area, in fact, was part of the residence of Countess Rosina Vercellana, Countess of Mirafiori, i.e. first the official mistress and then the morganatic wife of King Vittorio Emanuele II, who resided there during the King's brief stay at the Quirinale. When the king died in 1878, the complex was sold and parcelled out: all that remains of the old Villa Mirafiori is the main building, which houses the Faculty of Philosophy of Rome's La Sapienza University, and a small portion of the park.
Villa Crespi was built in 1907 for Commendatore Domenico Crespi. As early as 1937 it was home to the Conservatorio di S. Eufemia.
The main building, in Baroque style, has three floors marked by imposing stringcourses with windows adorned with balustrades and surmounted by eighteenth-century stucco frames with volutes and festoons. Inside, one can admire numerous splendid works of art related to the history of the St. Euphemia Conservatory. In the Chapel of the Conservatory are preserved: an Annunciation (c. 1580) attributed to Cesare Nebbia and coming from the Church of S. Urbano; a canvas with S. Eufemia (1631-1633) by Andrea Camassei, formerly in the Church of S. Eufemia (destroyed in 1812); a gilded silver reliquary head of Santa Martina, commissioned by Pietro da Cortona, who left it to the Conservatory. On the staircase leading to the first floor of the building is a painting of St Charles, St Francis and St Nicholas (first quarter of the 17th century) by Ottavio Leoni or Lioni known as 'il Padovano', formerly in the demolished church of St Urban.