The best way to approach this proud old town perched high on the cliffs is by boat , past the limpid blue waters of the Sdragonato cave and the Escalier du Roi d 'Aragon , a staircase cut diagonally into the cliff face , used by the soldiers of the Spanish king in an abortive siege of the town in the 15th century .
You can reach the town by boat and climb a staircase cut into the face of the cliff .