Il Castello

You drop onto the landslide of large basalt boulders that spills from beneath the Norman castle of Acicastello, ending on a sandy seabed between 18 and 22 m. The boulder field is cut with crevices and small canyons, and the profile stays flat enough that the whole itinerary — rated easy by the reserve, in light current — is dived at one comfortable level.

The crevices are refuges for brown meagre, groupers and scorpionfish, so most of the dive is spent moving boulder to boulder and checking the openings. The sand is where the surprises happen: rays, torpedo rays and anglerfish all turn up here. The signature sighting is the pearly razorfish, Xyrichthys novacula — numerous but shy, diving into the sand as you approach — so cross the open patches slowly before turning back over the boulders to ascend.