Known from documents since the 8th century A.D., the Aghinolfi Castle is an exceptional example of medieval military architecture, which attracted the attention of scholars already in the 19th century. The castle’s complex water supply system dating to the mid 15th century is particularly interesting for the knowledge of hydraulic technology. On the roof terrace of the octagonal keep, the original terracotta canalizations that collected water to convey it to the cistern were repristinated on the occasion of the 2001 restoration. Thanks to a glass floor, the bottom of the cistern exhibits copies of ceramic containers (the originals found there date to the late 16th century).