Blackberries hanging from brambles in front of a deep lock and moored narrowboat on the canal.

Denham

Just to the west of London's urban life is tranquil Denham Deep Lock. Passing through Denham Country Park on the Grand Union Canal, it's a great place for a country walk. It's called 'deep lock' because, with an 11 foot (almost 3.5 metres) drop, Denham holds the record for the deepest lock on the Grand Union.

Just above it is an aqueduct carrying the canal over Fray’s River, an artificial loop in the River Colne, originally created to supply waterpower to six flourmills.

Things to see and do

Planning your visit

Address
Colne Valley Park Visitor Centre (P&D), Denham Court Drive, Denham, UB9 5PG
Opening times
The towpath is always open.
Prices
Once you're parked up, it won't cost you a thing.
Toilets
For customers of the local pub/café.