Thames Estuary The new airport would be built on a man-made island in the estuary north of Minster-in-Sheppey There is also some discussion about the need for a Lower Thames Crossing in order to alleviate traffic congestion at Dartford. The Thames Estuary is the focal part of the 21st-century toponym, the "Thames Gateway", designated as one of the principal development areas in Southern England. The appellation Greater Thames Estuary applies to the coast and the low-lying lands bordering the estuary itself. These are characterised by the presence of mudflats, low-lying open beaches and salt marshes, namely the North Kent Marshes and the
Hilbre Islands some of which are privately owned. The most southerly building on the island is the Hilbre Bird Observatory, from which birds are continuously monitored in connection with a national network of observatories and ringing stations. In January 2011 it was announced that there would be no permanent ranger. Wirral Council said that they had had difficulty finding a ranger prepared to live without mains electricity or running water on the island. Hilbre Islands The Hilbre Islands ( ) are an archipelago consisting of three islands at the mouth of the estuary of the River Dee, the border between England and