Peñiscola is a fortified seaport, with a lighthouse, built on a rocky headland about 67 m high, and joined to the mainland by a narrow strip of land. Its history goes back to the Iberians and it was subsequently captured by the Carthaginians under Hamilcar Barca; legend has it that this is the place where he made his son Hannibal swear an oath that he would never be a friend of Rome.
The castle of Peñiscola is now a popular tourist attraction and the beaches and surrounding area are a popular family holiday resort. This website has more information.