The Sheppey Crossing is a bridge which carries the A249 road across The Swale (a strait in the North Sea), linking the Isle of Sheppey with the mainland of Kent. The four-lane crossing measures 21.5 m (71 feet) in width, at a height of 35 m (115 feet) over the water. The A249 links the M20 and M2 motorways to Sheppey. The bridge opened in 2006, and it provides an alternative highway to the neighbouring Kingsferry Bridge that was completed in 1959.