To the left of the path you can see three ancient oak trees with huge trunks. These are remnants of a medieval system, called pollarding, which was used until recent times. The oak trees had the dual purpose of providing shelter for domestic animals, while providing wood from the branches of the pollards. These trees may be more than 300 years old and may be home to more than 280 species of insects. Don't disturb grazing cattle.

Legend has it that it is called the Mole because it disappears underground into the chalk near Dorking during dry weather. But after wet weather these fields are often underwater. If you're lucky you may see a Kingfisher.

Continue for another 150 yards, then turn left along a bridleway. Cross the bridge over the motorway and follow the bridleway to the right.

The tower was constructed with a semaphore mast on top, as part of a chain of 15 semaphores, which were used to relay messages between the Admiralty in London and Portsmouth Dockyard. The system operated from 1822 to 1848.

The tower is open to the public on certain days. Inside there is an exhibition and from the top a panoramic view of Surrey's countryside.

Phone the tower manager on 01932 862762 for details of opening times.

If you have time along the way, it is worth exploring Chatley Heath, which is owned by Surrey County Council.

In the past most of this area would have been open heathland, but today there are only a few remnants left.

Heathland is a rare and declining habitat. It supports a unique range of species which are under threat, mainly due to changes in the way man manages heathland.

In the past they would have been grazed, and products such as wood and bracken harvested by local people. But over the last century these activities have declined. This has allowed trees and scrub to grow, which have shaded out the heather.

The Surrey Ranger Service in conjunction with local conservation groups, including the Lower Mole Project, have started to clear the scrub to reverse this decline.

On the left is Hatchford Park. A house has existed on this site since about 1740.

The grounds were laid out by Lady Ellesmere in the mid 1800s and covered more than 70 acres. Much of the layout still remains. There was a flower garden, rosary, rhododendron and azalea groves, a kitchen garden and a 60-acre pinetum full of rare conifers, many of them brought from abroad (much of this area is now known as Hatchford Wood).

Just inside the woods there is a mausoleum. This was built in 1921 and originally contained the remains of Sir Bernhard Samuelson with his wife and daughter, who had bought the estate in 1906.

From 1947 until recently the property has been a school.

Follow the narrow path and then go straight on along the road. Where the road bends to the left, carry straight on across a field, over a stile and along a winding path.

Keep to the waymarked path through the garden of May's Cottage. Go over a stile, turn left along the road and then slightly to the right.

After about 150 yards across a stile on your right, by the entrance to Yew Tree Cottage. Turn left and walk along the hedge line. Where the hedge turns left follow the waymark arrows across the field, and then through a wood, known as Old Oak Common.

On emerging from the wood turn left along the woodland edge, following it round and over a stile.

You will pass several ponds on this part of the walk. Ponds were once an extremely common feature of our countryside but they are now disappearing at a rapid rate. Ponds are no longer essential for watering stock and naturally fill in over time with silt and falling leaves.

Eventually land plants, and finally trees, start to invade and the pond disappears.

Ponds support a wide variety of plant and animal life, so it is important to conserve them. The Lower Mole Project has restored more than 20 ponds in the last 10 years.

Follow the path up the hill and bear right along the fence above the M25.

After about 100 yards cross the bridge over the motorway. Then go over the stile to the left and walk along the right hand edge of the field.

Cross the stile and turn right along the farm road.

Turn left along Chilbrook Road for about 300 yards, then right through a kissing gate by Chilbrook Farm and along the left hand side of a field. Go over a stile and cross the busy Downside Road carefully.

Turn left and continue along the pavement, which will take you back to the car park.

Walk instruction words and information about area have been taken, with thanks to The Lower Mole Countryside Management Project, from the Discover Downside leaflet available at local libraries or by sending a stamped addressed envelope A5 size to: Lower Mole Project, 2 West Park Farmhouse, Horton Country Park, Horton Lane, Epsom, KT19 8PL. A route description can also be downloaded from www.surreycc.gov.uk/lowermoleproject.