High Quality Content by WIKIPEDIA articles! Southend-on-Sea ( pronunciation (help·info)) is a unitary authority area, town, and seaside resort in Essex, England. The district has Borough status, and comprises the towns of Chalkwell, Eastwood, Leigh-on-Sea, North Shoebury, Prittlewell, Shoeburyness, Southchurch, Thorpe Bay, and Westcliff-on-Sea. The district is situated within the Thames Gateway on the north side of the Thames estuary 40 miles (64 km) east of central London. It is bordered to the north by Rochford and to the west by Castle Point. It is home to the longest leisure pier in the world, The Southend Pier.