Canal walk 10km

Stocker's Lake is an old flooded gravel pit of approx 90 acres (37.5ha) at Rickmansworth, Hertfordshire, England, within the Colne Valley Regional Park which is designated as a Local Nature Reserve.The lake is owned by Affinity Water and managed by the Herts and Middlesex Wildlife Trust assisted by the Friends of Stocker's Lake.

Rickmansworth Aquadrome is a 41-hectare (101-acre) public park and Local Nature Reserve in Rickmansworth in Hertfordshire. It is owned and managed by Three Rivers District Council.There are two lakes, which were created by the extraction of gravel for the original Wembley Stadium; Batchworth Lake is used for water skiing and Bury Lake is used by Bury Lake Young Mariners for sailing and canoeing.

Harefield Pit is a 1.8-hectare geological Site of Special Scientific Interest in Harefield in the London Borough of Hillingdon. It occupies much of a partially filled-in chalk quarry. It has two entries in the Geological Conservation Review database.It is an important Tertiary site in the London Basin, which displays a sequence through the Upper Chalk, Reading Beds and London Clay.