The Chess Valley Walk is a 10 mile route following the River Chess upstream from the small town of Rickmansworth in south-west Hertfordshire to the market town of Chesham in Buckinghamshire. The river is a natural chalk stream, fed by chalk aquifers in the Chiltern Hills. The route can be followed in either direction and is clearly waymarked. Most of the route is on public footpaths but there are short sections on roads. Along the way there are historic buildings and estates, water meadows, ancient field systems and nature reserves. From start to finish the walk, which starts at the confluence of rivers where the rivers Chess and Gade form the River Colne, visits Little Lady's Wood and then crosses over the M25 London Orbital. After the noise dies down the walk continues north past Church End and Sarratt Bottom before turning westwards through Frogmore Meadow Nature Reserve and past Chenies Bottom to reach Latimer. The walk continues on a north-west course now to its conclusion in Chesham via Frith Wood, Milk Hall, Chess Mount and Waterside.