The settlement is built on an area of flat land formed by silting at the head of the estuary of the River Dee. Located on the A548 road, Sealand is near to the Chester dormitory communities of Blacon and Saughall.
RAF Sealand was originally a civilian airfield and was taken over by the military in 1916 for training. No 30 Maintenance unit was formed there in 1939. In 1951 the base was taken over by the United States Air Force, and handed back to the RAF in 1957.
As a result of defence cuts announced in 2004, RAF Sealand was closed in April 2006.