Farnetella's physiognomy is caracterized especially by the castle. The work for this building started in December of 1889, commissioned by Adolfo Ferrari. Adolfo decided to build a big place where he could met important and rich men, similar to the other castle near Siena. The castle was finished in 1903 and it took a lot of money by Adolfo Ferrari so much that remained unfinished.

Inside the castle there a lot of forniture and fresco also a nice wood decorations of the dining room by Giovanni Sammicheli. Today the castle and the cottage adjoining are of private property and so not open to the public despite several requests from visitor and inhabitants.