The city council owns all the beaches, which are divided into named sections by groynes—the first of which were completed in 1724. Eastwards from the Hove boundary, the names are Boundary, Norfolk, Bedford, Metropole, Grand (referring to the four hotels with those names), Centre, King's, Old Ship, Volk's, Albion, Palace Pier, Aquarium, Athina (where the MS "Athina B" ran aground), Paston, Banjo, Duke's, Cliff, Crescent and Black Rock. Cliff Beach is a nudist beach. Beyond Black Rock, the cliffs (part of the Brighton to Newhaven Cliffs Site of Special Scientific Interest) rise to more than and there are three small beaches at Ovingdean Gap, Rottingdean Gap and Saltdean Gap. All are connected by the Undercliff Walk, which has been affected by several cliff falls since 2000.