There’s a lot of options for circular walks from Newland’s Corner. This one is a variation on most as it takes in the Merrow Downs Trig Pillar and Chantries Wood. The route is a mix of large well-signed trails and cuts though woods with lots of similar looking paths. For these I’d recommend a GPX route or Explorer map to keep you on track.
From the Newland’s Corner Car Park take the path that heads north to the right of the Visitor's Centre. Follow paths to the edge of Merrow Downs Golf Course where you’ll find the OS Trig Pillar. From the pillar head west then south through the woods until you reach the North Downs Way. Follow the North Downs Way as it south-west past St Martha’s Church and down to Halfpenny Lane.
Cross over Halfpenny Lane and leave the North Downs Way, heading south-west through Chantries Wood. After the campsite, take a path heading steeply downhill to the south-west until you meet a path T-junction after a hedge. Take a left, heading east along the hedge until you get back to Halfpenny Lane. Take a right onto Halfpenny Lane, then a right immediately onto a footpath rather than following the Lane.
At the end of the footpath you’ll re-join Halfpenny Lane. Follow this south for 100m crossing the Tilling Bourne stream where you’ll see the entrance to the Gunpowder Mills on the left. Enter the Gunpowder Mills and follow the path through it for ~1km until you meet the Downs Link. Take some time here to see the remains of the old East India Company Mills. There’s information signs at the main entrances with leaflets explaining the different remains.
Once you reach the Downs Link you’ll need to leave the Mills and continue east though a field remaining parallel to the Tilling Bourne. Continue through an estate of some very nice houses set around Postford Lake and Waterloo Pond. You’ll emerge onto the A248 Chilworth Road. Follow the road east for 200m and take a left onto Guildford Lane. Follow Guildford Lane north-west for 500m then take a path on the right. Follow this path for just over 1km through woods, past a farm and then the final ascent to Newlands Corner.
For a shorter version of this you could save ~1km by heading directly west from Newlands Corner, missing out the Trig Pillar. Another 1k can be saved by walking south down Halfpenny Lane instead of the Chantries Wood section. I highly recommend the full route though as it takes in several of the main points of interest in the area.