Two kilometres inland and 200 metres above the sea, Diano Castello is the original settlement from which the coastal resort took its name. The medieval village is a compact maze of narrow lanes, stone arches, and old houses pressing together on the hilltop — completely different in character from the beach strip below. The parish church of Sant'Erasmo dates from the 12th century, and the remains of the medieval walls and towers are still visible around the perimeter.
The views down to the coast from the village edge are excellent on clear days — the whole curve of the bay laid out below, with the Ligurian Alps pressing in from behind. It takes about 20 minutes to drive up from Diano Marina, and it's a good objective for anyone who needs a break from the beach.