This large shell midden (locally known as Cockleshell Island) is situated on the eastern shore of Kingswood Pill, which lies between the A477 road to Pembroke Dock and Cosheston Pill to the north. The area dries out at low tide exposing mud flats which are not suitable habitats for the oysters, therefore it is likely that the shellfish were gathered, either by hand into boats at low tide from sites elsewhere, or by towing an oyster dredge behind the boat.
The plan view of the midden is a flattened D shape, the flat side resulting from erosion by the sea. The midden measures 60 metres long by 10 metres wide with a visible depth of nearly one metre.
The "sea cliff" behind it is an average of 1.5m high but there is a place where this has been trodden down to give easy access down from field to shore level.
Near the midden the stem post of a boat rises out of a matrix of mud and shells.
Quite near there is a rectangular dock cut into the mud while some 200m away there is another rectangular "dock " cut into the turf of the shoreline, complete with a mooring post.

From information provided by David James, Hon secretary of West Wales Maritime Heritage Society.