Aci Castello is a small coastal village a short drive north of Catania, strung along the Riviera dei Ciclopi where the volcanic shoreline drops straight into the Ionian Sea. The village takes its name and its silhouette from the Norman castle that crowns a black basalt sea stack at the water's edge — a fortress raised in the twelfth century directly onto the lava, so that the rock and the masonry seem to be the same thing.
The castle is the reason most people come. It is compact, but the climb up to it rewards you with a small archaeological museum inside and a viewing terrace that looks out over the water and back along the coast toward Etna. Below the walls, the shore is all dark rock rather than sand, and on warm days locals lay out towels on the lava ledges and swim from the rocks. There is no beach in the conventional sense, but the swimming is good and the setting is dramatic.
The village runs almost imperceptibly into Acitrezza to the north, and a coastal path links the two in about half an hour on foot, passing the famous Faraglioni dei Ciclopi sea stacks along the way. Aci Castello itself is an easy ten minutes from central Catania by bus, which makes it a natural half-day outing — climb the castle, swim from the rocks, and walk on to Acitrezza for lunch at a seafront trattoria.