Horsenden Hill (//; grid reference TQ 161 843) is a hill and open space, located between the Perivale, Sudbury, and Greenford areas of west London. It is in the London Borough of Ealing, close to the boundary with the London Borough of Brent. It is one of the higher eminences in the local area, rising to 85m (276 ft) above sea level, and the summit forms part of the site of an ancient hillfort. It is the site of a trig point, TP4024.
It is known that 2500 years ago Iron Age people settled on what today is called Horsenden Hill as large amounts of pottery have been discovered. In fact, in 1978 the Iron Age settlement on Horsenden Hill was declared as an Ancient Scheduled monument by English Heritage.
It was probably during Saxon times that the hill acquired its name originally "Horsingdon" - the last syllable don meaning hill fortress.
In the Second World War the hill was the site of an anti-aircraft battery, which was used to protect the local factories from air attack. There are currently two disused reservoirs built into the hill on the south side.
To the south and east the hill is bound by the Grand Union Canal (Paddington branch), which runs roughly along the 100 ft (30 m) contour line.
To the south west lies Perivale Wood Local Nature Reserve, run and maintained by the Selborne Society. A scenic spot on the Capital Ring in the summer months, Horsenden Hill offers fine views across west London, northwest London and beyond; places visible include Harrow on the Hill, the new Wembley Stadium, Northala Fields, planes coming in to land at Heathrow Airport, and on a clear day, the Home Counties of Surrey, Berkshire and Buckinghamshire.
Two golf courses cover parts of the hill on the south and east sides. Nearby stations are Perivale tube, Sudbury Town tube and Greenford tube and rail stations. There is also a visitors centre located at Horsenden Farm on the east side of the hill and a public car park on the north side. The visitors centre closes at dusk. Access to both is via Horsenden Lane in North Greenford.
In the summer of 2006, as part of the Horsenden Grazing Project, Highland cows were introduced to graze in a fenced-off area. Various other breeds of cow have subsequently been used.