Towers 'R' & 'S' are no longer, 'R' is buried as part of the foundations of the Bartlett Hospital and 'S' was lost to the sea in the 19th century
On the same theme the Roman's had a castle situated by what is termed 'The Dip' and known as Walton Castle, again a fortress demolished by the power of the waves details of this can be seen here http://www.wuffings.co.uk/WuffSites/Walton.html
Tower 'W' is the first of the towers running North from Bawdsey at East Lane, this one is lived in and is currently up for sale, like others along the coast this would almost certainly have been in danger of being swallowed by the sea if preventative measures on coastal erosion hadn't been taken