Alnmouth is a village on the north-east coast of England, some due north of Newcastle upon Tyne, south-south-east of Berwick Upon Tweed, and to the east-south-east of Alnwick. The village is built on a promontory on a spit of land bordered to the east by the North Sea and to the south and west by the estuary of the River Aln, falling from around above Mean High Water level at the north of the village to in the south-west. The geology of the North East of England around Alnmouth is a superficial layer of glacial till in the form of boulder clay lying on often outcropping Whin Sill, a carboniferous limestone, with peat deposits, and, at the coast, wind-blown sand including a coastline dune system which has evolved over the last 10,000 years. The coastline of the county is a series of headlands and bays — such as at Alnmouth — with wide, sandy beaches, the result of differential erosion of ice-age deposits. Alnmouth's south-beach dune is calcerous, containing mainly marine-animal shell, and is only 2–300 years old. Alnmouth lies at the south-east extent of low hills such run down from the Cheviot Hills to the coast. Its hinterland is an open agricultural landscape of arable land and pasture, with broadleaf woodlands in river valleys such as of the Aln, and some forestry plantations. Its history is of medieval tree-clearance and the establishment of scattered settlements and farms with complex field patterns. Alnmouth's coastline has multiple protected area designations. It lies at the southern end of the Northumberland Coast Area of Outstanding Natural Beauty and the (non-statutory) Northumberland Heritage Coast, both of which seek to protect its landscape in all aspects. The saltflats of the estuary and the south beach dune are a Site of Special Scientific Interest listed in 1988 as Alnmouth Saltmarsh and Dunes for its varied plant community. As part of the Environment Agency's Northumberland 4shores Project, in 2006, flood banks protecting of estuarine pasture were breached and shallow ponds created, to allow tidal action to recreate saltflats to provide habitats for wading birds, dissipate wave energy, and diminish the potential for flooding. The golf course area, north of the village, is registered as common land. Most of the village was designated as a conservation area in 1972 — areas of recent building in the north are excluded. The architecture of the town is a mix of