A walk along the meandering River Brent with its adjacent meadows and colonies of bats.
Distance 3.5 miles (5.7km)
Minimum time 2hrs 45min
Level of difficulty Medium
Paths Mainly grassy riverside tracks that can get muddy
Landscape Riverside meadows and wildlife
Suggested map aqua3 OS Explorer 173 London NorthTQ 153805; Hanwell railTQ 163832; Perivale tube
Dog friendliness Not allowed in churchyard
Parking Plenty in streets adjacent to Hanwell rail
Public toilets Brent Lodge Park
Notes To return to start, take 95 bus from Western Avenue to Greenford Red Lion, then E3 to Hanwell station
1 From Hanwell railway station follow the road in front as it bends to the left. At the end turn left and head towards the viaduct. Just before it, cross the road and join a tarmac path to the left of a small, enclosed recreation ground. A few paces further on take the paved path on the left and continue as it becomes a track running beside the Wharncliffe Viaduct. Isambard Kingdom Brunel designed the viaduct in 1837 and it was used by the Great Western Railway to carry trains from London to Bristol.
2 Enter the gates to Brent Lodge Park and go up the steps to your left, past the fingerpost signed 'Brent River Park'. At the end of the meadows follow the path through the trees as it runs alongside the river. Continue across the grass, past St Mary's Church on your right, and go down a set of steps then through a wooden gate.
Cross the iron bridge to take the right-hand path. Just a few paces further take a right-hand fork to join the riverside track. When this meets another, turn right and head towards the footbridge. Cross it and turn left across a footbridge over a ditch - carry on, with the river on your left. Keep ahead at the next bridge to join a prominent path. At the next fork turn left. Now carry on past a wooden bridge and then go to the right of an extended area of reed beds.
3 Continue ahead past a weir. Behind the steep bank on your right is the Bridge Avenue Extension. If the riverside track is muddy then head for the grassy path at the top. Keep ahead to the left of a sports field. At the end cross Ruislip Road and join a path on the left, signposted 'Brent River Park Walk'.
After two more weirs, the second of which is enclosed by railings, you will see Perivale Golf Course on the left. Continue on this path as it runs parallel to the road and merges with the pavement for 20yds (18m) before veering to the left under the railway bridge. After a metal footbridge go up some wooden steps. Pass to the left of Gurnell Sports Centre and bear left along a narrow, gently descending track, following the river along the edge of the sports field.
4 After the sports field turn left, towards Argyle Road. Turn right here until you reach the traffic lights. Cross the road and turn left along a tarmac path signposted to Perivale Lane. At a crossing of paths keep ahead along a fenced path that slices through Ealing Golf Course. At the end turn left to cross a wooden bridge. Ahead is the white-timbered steeple of the 12th-century St Mary the Virgin Church in Perivale.
5 At the lychgate turn left and then right into Old Church Lane. At the end cross the footbridge over the busy Western Avenue to reach Perivale tube.
This walk is notable for its pipistrelle bats. Many of these warm-blooded mammals hang from the nooks and crannies of Wharncliffe Viaduct, coming out at dusk to feed on insects along the river, in the area just beyond St Mary's Church. You won't see them in winter though, as this is when they hibernate, due to lack of food supplies.
There are birds to see too, especially in the reed beds, which provide not only a nesting site for reed warblers, but also feeding areas for migrating birds, especially in autumn.
On the opposite bank you'll see willows that have been traditionally pollarded. They resemble enormous tufted bulbs sprouting from the top of the trunk.
Near the end of the walk, the churchyard of St Mary the Virgin, in Perivale, is a haven for wildlife and features the rare black poplar tree. The church is now an arts centre and hosts plays and concerts during summer weekends.
Take a look at the Millennium Maze in Brent Lodge Park - follow the path to the right of the steps. It was created using 2,000 young yews on the site of an old bowling green and emphasises just how slowly these trees grow. Yews are ideal for borders and mazes as they are easy to prune. Today, they have a role in cancer treatment - an extract derived from their crushed leaves is used to produce drugs which inhibit cells from dividing and spreading the disease.
The view of the viaduct from Hanwell Bridge on the Uxbridge Road is spectacular and it just so happens that the Fuller's Viaduct pub is strategically placed near the bridge. Otherwise, for something completely different, turn left before the footbridge in Western Avenue to find Starvin Marvin's Diner for a big, American, all-day breakfast.
If you're out walking in the afternoon you may see some of the colonies of pipistrelle bats that have set up home in the brickwork of Wharncliffe Viaduct. This species, London's commonest bat, is so small that it can fit into a matchbox. It flies up to treetop height, searching for tasty midges to eat. In the fading light they locate food by sending out high-pitched sounds that echo back, giving them information about the location of their prey. As walkers' heads are not on their menu, they will probably do everything they can to avoid you.