Kent is a county in South East England and one of the home counties. It borders Greater London to the north west, Surrey to the west and East Sussex to the south west. The county also shares borders with Essex along the estuary of the River Thames, and with the French department of Pas-de-Calais along the English Channel. The county town is Maidstone. Canterbury Cathedral in Kent has been the seat of the Archbishop of Canterbury, leader of the Church of England, since the conversion of England to Christianity by Saint Augustine began in the 6th century. Between London and the Strait of Dover, which separates it from mainland Europe, Kent has seen both diplomacy and conflict, ranging from the Leeds Castle peace talks of 1978 and 2004 to the Battle of Britain in World War II. England relied on the countys ports to provide warships through much of its history; the Cinque Ports in the 12th–14th centuries and Chatham Dockyard in the 16th–20th centuries were of particular importance. France can be seen clearly in fine weather from Folkestone and the White Cliffs of Dover. Hills in the form of the North Downs and the Greensand Ridge span the length of the county and in the series of valleys in between and to the south are most of the countys 26 castles. Because of its relative abundance of fruit-growing and hop gardens, Kent is known as The Garden of England. The title was defended in 2006 when a survey of beautiful counties by the UKTV Style Gardens channel put Kent in fifth place, behind North Yorkshire, Devon, Derbyshire and Gloucestershire. Kents economy is greatly diversified. Haulage, logistics, and tourism are major industries; major industries in north-west Kent include aggregate building materials, printing and scientific research. Coal mining has also played its part in Kents industrial heritage. Large parts of Kent are within the London commuter belt and its strong transport connections to the capital and the nearby continent makes Kent a high income county. Twenty-eight per cent of the county forms part of two Areas of Outstanding Natural Beauty: the North Downs and The High Weald.