This collection is on show in an elegant building dating back to the end of the 15th century. There is a beautiful porticoed courtyard with finely sculpted Renaissance capitals on two columns.

The collection belonged to Herbert Percy Horne, an English art critic and scholar noted for his studies of Botticelli.
On display there is a panel by Giotto depicting St. Stephen, works by Masaccio and of the 16th century painter from Siena, Domenico Beccafumi, as well as preliminary works for sculptures attributed to Giambologna and Bernini.