The Old Waterworks, Southend-on-Sea. Photo Cristina Sousa-Martínez September 17, 2017 692 × 923 The Old Waterworks, Southend-on-Sea. Photo Cristina Sousa-Martínez The Old Waterworks, Southend-on-Sea. Photo Cristina Sousa-Martínez. The Old Waterworks, Southend-on-Sea. Photo Cristina Sousa-Martínez.