The A20 is a major road in south-east England, carrying traffic from London to Dover in Kent. Parts of the route date back to turnpikes established in the early part of the 18th century. The line of the road throughout Kent runs closely in parallel with the M20 motorway.

Dover is a town and major ferry port in Kent, South East England. It faces France across the Strait of Dover, the narrowest part of the English Channel at 33 kilometres (21 mi) from Cap Gris Nez in France. It lies south-east of Canterbury and east of Maidstone. The town is the administrative centre of the Dover District and home of the Port of Dover.