Amersham is a market town and civil parish within Chiltern district in Buckinghamshire, England, 27 miles (43 km) north west of London, in the Chiltern Hills. It is part of the London commuter belt. Amersham is also 15 miles (24 km) from Aylesbury and 13 miles (21 km) from High Wycombe.There are two distinct areas: Old Amersham, set in the valley of the River Misbourne, which contains the 13th century parish church of St.