Thanet, Isle of (thănˈĭt) [key], former island forming the NE portion of Kent, SE England, bounded by the North Sea and branches of the Stour River. The isle was occupied by the Romans, who had a fort guarding the Wantsum, the channel that once separated the isle from the mainland. Silting and land reclamation have since joined the isle to the mainland. The surface is generally low, but cliffs form part of the shores. Most of the towns, which include Ramsgate, Margate, and Broadstairs and Saint Peter's, are seaside resorts.