Easy going on cycle tracks, bridleways and country roads.
Only one muddy bit!
16km

Start GR174299 Parking at the end of Queensway or at Southwater GR159263 

• Leave the small car park at the bottom of Queensway heading south east for 350m then turn right to cross the river Arun and ascend Denne Hill. Cross a plateau and reach Coltstaple Lane GR169278
• Turn right for 200m and then left into Reeds lane. After 500m turn left into Jackrell's lane. Follow the lane for a further 2.5km (name change to Polecat lane) until the junction with Broadwater lane, GR172252.
• Turn right into Bar lane and in about 100m, just past the 'Bridge Inn', turn sharply right onto the Downs link heading northwest
• Keep on this bridleway passing at 1km Southwater sewage works and  under the A24; In a further .8km Southwater cycles.  The route may now take you under a main road.
• After 3.5km from 'the Bridge Inn' you should have reached the former junction of the Shoreham - Horsham railway with the Horsham - Bognor line, at Junction Cottage.  Leave the Downslink at this point heading east and passing across the extensive playing fields of Christs Hospital, the country's most well off independent school.
• After 1km heading more or less east, the bridleway crosses a  minor road (Two Mile Ash) on a staggered junction.  Continue east to a fairly major road.

Depending on the time of day . . .

• If in the rush hour turn right, past the 'Hen and Chickens'and then left into Southwater street.  Continue on  a bridge over the A24 and follow the road round until  you come to Pedlars Way and turn north back to Horsham
• If outside the rush hour turn left to a roundabout and find the byway going east across the A24.  You will need to ride (on the verge) against the flow of the traffic to cross using a gap in the central reservation.
  Ayez courage mes braves!
  The byway emerges on Southwater street so turn left and in 300m  left again into Pedlars way and so back to Horsham

The rock surrounding Horsham is Weald Clay. However Denne Hill is sandstone which was quarried for 'Horsham stone'; Used as paving slabs and roofing tiles
(Sussex Stones by Roger Birch. Rober Birch 2006. ISBN 0-9551259-0-1). 

Christ's Hospital official website