For the first half century or so of its existence Devonport was geographically isolated from the rest of the North Shore, and was sometimes called "the island" by the local inhabitants. Only a thin strip of land beside the beach at Narrow Neck connected Devonport to Belmont and the rest of the North Shore peninsula. In the late 19th century the mangrove swamp that stretched from Narrow Neck to Ngataringa Bay was filled in to form a racecourse, now a golf course. A new road was built along the western edge of the racecourse allowing more direct travel to the north.