TEWIN means "Sons of Tew", a Saxon pagan god. He would have approved, surely, of the fresh morning that greeted my departure from the village green, though not, perhaps, understood my visit to St Peter's church, a mile to the south.

A Saxon church once occupied the site, where today cedar, lime, yew and oak adorn the churchyard, along with a mighty sycamore that is slowly pushing aside the tomb of Lady Grimston, as though resenting her presence.

The right of way runs from the churchyard towards the Mimram, then alongside the river to Tewin Bury Farm and, beyond, through a small wood where a bridleway leads to Digswell Water.

Grand views here across the valley, where the taller buildings of Welwyn Garden City peer over the green canopy of extensive woodland.

The valley was occupied by Belgic tribes, although more tangible evidence of man's occupation is seen as you climb the hill towards Harmer Green.

Look back for splendid views of the Digswell Viaduct, 40 brick arches a hundred feet high. It was built by Lewis Cubitt on the style of a Roman aqueduct, and took only two years to complete, a credit to the Victorian engineers. Even so, Queen Victoria refused to cross it on her way to Balmoral, opting instead to traverse the valley by coach.

Harmer Green brought the first signs of life so far on my journey - a gaggle of geese. Judging by their curiosity, they don't see many people either. Outnumbered, I let them be and headed north into the woods.

An "earthwork" indicated on the map lies on private ground beyond a dilapidated wire fence, so to explore is to trespass. One surmises it to consist of a shallow hollow, with old, pollarded trees, some sort of ancient settlement, maybe.

I aimed for the far corner of Harmergreen Wood, where the path passes beneath an archway formed by the branches of the trees that border it. It looks as though it has been unchanged for centuries.

A distant siren and the drone of an unseen aircraft were reminders of today's modern world.

A quiet lane runs east. It exists thanks to the Romans, whose original road came this way. Today's modern road turns away, but a bridleway continues to Datchworth Green, where the Plough is ideally sited for refreshments. Inside, there's a notice: "On this site in 1897 nothing happened". Very interesting!

Another (muddy) bridleway leads into Bramfield Woods where, after half a mile, I returned to the road where the Clibborn's Post stands forlornly by the roadside. It's said to mark the grave of one Walter Clibborn, who was captured committing a robbery.

He was hanged, and buried here. The original post has long gone, its replacement being dated 1927. They've mis-spelled his name, with just one "b".

Back in the woods, a notice with a photograph asked anyone passing to keep an eye out for a lost cat. Alas, I saw no sign of him. To search these woods would be a forlorn task, I fear.

Beyond, at sleepy Bramfield, the post office is housed in a thatched cottage. If there is a prettier one in the country I have yet to see it.

At St Andrew's church, a flagged path leads between limes past a row of Celtic crosses. They mark the graves of the Harrison family. Getting out on foot, that's the way to explore. What I discovered at Bramfield proves it.

I headed for Bramfieldbury, where the right of way, unusually, takes a diversion around the house. Did someone once wield some influence here, to keep Joe Public away? Further on, a faded blue arrow points across a huge field, where muddy footprints confirm you're on the right of way. For those who enjoy the smells of the countryside, a 200-yard long pile of manure awaits, just beyond a derelict barn.

Beyond Bacon's Farm, the path picks its way to a lane where rights of way circumnavigate Marden Hill House, crossing open parklands and meadows, enabling you to see the house from different angles.

Finally, it passes through more woodland and traverses a huge field on its way back to Tewin.

Routefinder

Start and Finish: Village Green, Tewin

Abbreviations

l = left; r = right; n. s. e. w. = north, south, east, west; br = bridge; r.o.w. = right of way; PH = public house; m = mile; s/post = signpost; f/post = fingerpost; b/way = bridleway; ch = church; c/yard = churchyard.

From School Lane, turn r over stile into field, l at f/post to St Peter's ch | Pass through gate, s.e. corner of c/yard, to River Mimram, r to Tewin Bury Farm | At "Reception" turn l up hill, l through gap in hedge | Take b/way to Digswell Water | Turn r 150 yds, r again at s/post for Harmer Green, l to Harmer Green | Head n.e. for 0.5 m, then l at s/post into woods | At f/post, head n.e. at sign 4/SV/26 to the "Earthwork", then l to far corner, Harmergreen Wood | Take the Roman Road to Datchworth Green | Take the rd for Watton for 0.5 m, turn r on Public Byway 9 for Bramfield | After 0.5m turn right to the road, then l "Clibborn's Post" on r in 0.5m | Turn l opp Tewin Hill, rejoin path through woods to Bramfield | At ch head w. past Grandison Arms for Bramfieldbury, 0.5 m beyond, turn l across field at pale-blue arrow on f/post, aiming for a derelict barn | From Bacon's Fm, follow r.o.w. around Marden Hill House to Tewin.

Pubs: Tewin: Rose & Crown. Datchworth Green: The Plough. Bramfield: Grandison Arms

Reproduced from Limited Edition magazine, exclusive guides to living in Hertfordshire, Middlesex and the London Borough of Barnet (01923 216295).

For a printable map of the walk, please click the image below.