Explore The Lost River Fleet on Hampstead Heath

The route of the River Fleet, one of the Lost Rivers of London is now almost completely built over, but its path is still fascinatingly visible. Starting at the source in front of Kenwood House on Hampstead Heath the route passes through Hampstead, Kentish Town, Camden, St. Pancras, Kings Cross, Clerkenwell and Farringdon to where it can still be seen flowing into the River Thames at Blackfriars. This post is about the start of the River Fleet on Hampstead Heath. Other posts will follow it down to Blackfriars.

1. The Source of the River Fleet

Kenwood House, Hampstead Heath marks the start of the walking trail at its most northern point at an altitude of 113m above sea level. Depending on the time of year, and how wet it has been recently, you may notice that a tiny stream meanders out of a small group of trees. The near permanent wetness in the ground turns into a small stream that creates a boggy patch in the beautiful lawns in front of Kenwood House. This is the source of the emergent River Fleet. It flows into the pond which is an accumulation of water caused by damming the river. 


Hampstead Heath is a large, ancient London park, covering 320 hectares (790 acres). The area to the north of the Heath (where the source is) is the Kenwood Estate and House - a total area of 50 hectares (120 acres) which is maintained by English Heritage. The original house dates from the early 17th century. The orangery was later added in c.1700.

Walking Notes: From the source, walk back up to Kenwood House and continue down the path in front of it (heading east) until you reach a gate on the left hand side with some wooden sheds next to it. Go through that gate and continue downhill on that path.

2. Down We Go to Highgate Ponds

You are now at an altitude of 87m having dropped 26m since the source of the River Fleet. Here you can clearly see the way that the Highgate Ponds have been formed by damming the flow of the River Fleet. The two ponds here show a marked difference in elevation. Here the two sides of the valley can also been seen as the river continues its flow downhill. They were originally dug in the 17th and 18th centuries. They include two single-sex swimming pools, a model boating pond, a wildlife reserve pond and a fishing lake.

Walking Notes: From here continue downhill alongside the ponds, before crossing to the other side at the men's bathing pond. As you walk along the path alongside the men's bathing pond, if it has been wet, you may see standing water on the right hand edge of the path. This has leeched out of the upper sands on the hill, and is running into the Fleet River valley.

3. Valley View

Take a seat and look north. From here you can clearly see the valley of the River Fleet as it flows down through Hampstead Heath. There are marked valley sides to the left and right of the ponds.

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