It stands at the
south-western boundary of the town and overlooks the valley of the Celano-Foggia
sheep-track and the river Fortore. Angevin records (1320) refer to the
settlement by the name of “Collis Tortus”. The conformation of the
town bears witness to the transformation of the original nucleus where the
Franciscan church rises, with the walled burgh defended by the cylindrical keep,
built at the time of Queen Giovanna I (circa 1340) as part of a general
reorganisation of the defences of the hollow of St. Mary and the valley of the
Fortore. The wall structures are founded directly upon an outcrop of rock. The
masonry bond is mixed, with cut stones well set in somewhat irregular rows.
There is a cistern in the basement. The defensive systems are represented by a
surviving arrow slit, an underground passage (the valloncello) and, most
of all, by a striking projection on monolithic stone corbels. On the ruins of
the old castle Marquis Rota built a four-sided palace with an inner courtyard
which today houses the city hall. Rising to a height of 25 metres, this building
is unique in Molise, though it has interesting analogies with some Swabian/Angevin
keeps found in Apulia (Lucera), Abruzzo (S.Stefano di Sessania or the enceinte
tower at Bominaco), Basilicata (Tricarico, Cirigliano, S.Mauro Forte), Campania
(Velia), Calabria (the tower of Malvito) and Sicily (Salemi). The most
significant example is the stone keep at S.Marco Argentano in Calabria, which
replaced an older wooden donjon on a motte and was built by Robert
Guiscard before 1051.