Southend-on-Sea is a resort town on the Thames Estuary in Essex, southeast England. The long Southend Pier is serviced by a small train and has a museum at its shore end. Nearby, Adventure Island is an amusement park with fairground rides and water slides. The Cliff Lift, a century-old funicular, clings to the hillside and offers coastal views. Sea Life Adventure aquarium is home to otters, clownfish and turtles.