The defining experience of Southend is the walk (or the pier railway ride) out along Southend Pier, at 1.34 miles the longest pleasure pier in the world. The seafront is anchored by Adventure Island, a busy free-entry amusement park, and the Sea Life Adventure aquarium. The unusual Southend Cliff Railway lifts you up from the seafront to the cliff-top gardens. Inland, the Beecroft Art Gallery, the small Southend Central Museum and the wonderfully odd Cranfield's Curiosity Cabinet make up a small but interesting indoor circuit. The Kursaal, an Edwardian entertainment dome at the east end of the seafront, remains an architectural landmark. Out at the muddy mouth of the Thames sits the unsettling Graveyard of Lost Species, a slowly sinking boat carved with the names of vanished Estuary fish and birds.