Spurn Head lies at the head of which English estuary?

Spurn is a narrow sand tidal island located off the tip of the coast of the East Riding of Yorkshire, England that reaches into the North Sea and forms the north bank of the mouth of the Humber Estuary. It was a spit with a semi-permanent connection to the mainland, but a storm in 2013 made the road down to the end of Spurn impassable to vehicles at high tide.

The island is over 3 miles (5 kilometres) long, almost half the width of the estuary at that point, and as little as 50 yards (46 m) wide in places. The southernmost tip is known as Spurn Head or Spurn Point and is the home to an RNLI lifeboat station and two disused lighthouses. It forms part of the civil parish of Easington.

Spurn Headcovers 280 acres (113 ha) above high water and 450 acres (181 ha) of foreshore. It has been owned since 1960 by the Yorkshire Wildlife Trust and is a designated national nature reserve, heritage coast and is part of the Humber Flats, Marshes and Coast Special Protection Area.