The castle that gives the town its name is one of the most complete surviving Hospitaller fortifications in central Italy. First documented in 1075 as a Benedictine hospice, it passed to the Knights of St John in the 12th century, who rebuilt it into the compact fortress visible today: a square plan with circular towers at the corners, thick stone walls, and an interior courtyard enclosed by two-storey loggias.
The structure is well-preserved and the interior courtyard has an austere, functional beauty. The loggia arcades give the fortress an unexpectedly elegant character for a military building. The castle can be visited on guided tours — check locally for current opening hours, as they vary with the season. It is the primary reason to come to Magione rather than simply drive through.