Sea of Change - Southend-on-Sea.Sunken Garden/Marine Garden/Children’s Corner/Peter Pan Playground/Adventure Island Gallery.01:Children’s Play Area Sunken Garden. 02:1920s Children’s Play Area Sunken Gardens. 03:Children’s Play Area Sunken Gardens. 04:1950s Peter Pan Playground. Peter Pan Playground. 06-11:1971 Peter Pan Playground.Images Subject to Copyright.