This church is easily recognisable thanks to its octagonal bell tower built by Charles I in 1274. Opposite the entrance a long staircase leads to St Michael's cave, where the entrance to the church is marked by a superb bronze door (1076). The church itself, an actual cave, has been modified and added to over the centuries but has retained its irregular natural vaulting. At the end of the choir stands the marble statue of St Michael - his sword is removed every year and carried in procession through the town.