The castle of Olmo Gentile is made of two deeply different parts: the tower and the keep.
The square tower, of sandstone, was probably built in the XII century. On its top are four big stones, that probably were the support for a balcony, today disappeared.
The keep was built in 1681 for the bishop Gozzani, running away from Acqui; he lived here for some time. Inside, before the recent restoring, there were still some frescos – on the stairs and sone ceilings -, a beautiful fireplace and pavements.
The ancient door to the fortified village came down in 1951 (its supports are still visible on the walls), while on the back there’s a building, called the “serfs’ house”, restored in 1818 and used as a home until 1970.