With 7 miles of seafront, there is a fantastic choice of beaches at Southend-on-Sea, shown on Landranger map 178. Try your hand at water sports at the Southend Marine Activities Centre or explore the longest pleasure Pier in the world. Across the Thames Estuary is the town of Rochester with its Norman castle, cathedral, farmers' markets & festivals. With this map you will receive a code for use on your i OS or Android smartphone or tablet. Find our more at Mobile Download FAQ. The OS Landranger map for Thames Estuary is available in both the standard paper version & weatherproof " Active" version.