From Hertford Heath to Great Amwell

Perched on the edge of the river cliff above the Lea Valley, is the small, attractive village of Great Amwell. It has a pub, the George IV, and a Norman church nestled in a steeply sloping, leafy churchyard, with some good monuments and mausolea, including the Mylne family's.

'Amwell! Perpetual Be Thy Stream'

Below the church hill is an attractive small lake with an island, on which stand weeping willows and an urn on a pedestal, commemorating Sir Hugh Myddelton. He constructed the New River between 1609 and 1613. Its purpose was – and still is – to carry fresh drinking water to Stoke Newington and on to London. The memorial was designed by Robert Mylne, the architect for the New River Company from 1767 until 1800. The inscription on the memorial reads:

'From the Spring at Chadwell 2 miles west and from the source of Amwell the Aqueduct meanders … conveying health, pleasure and convenience to the metropolis of Great Britain …'.

On another island Mylne erected a second monument inscribed 'AMWELL! Perpetual be thy Stream Nor e'er thy spring be less…'. Mylne was buried in the nearby churchyard in 1811.

Unfortunately, soon afterwards the stream failed in dry weather and the New River had to be extended northwards to the Lea between Hertford and Ware. Here the New Gauge, rebuilt in 1856, controls how much water enters the New River. Remarkably, the New River is still an important element in London's water supply.

Further west, away from the Lea Valley and at the south end of the well-wooded Hertford Heath, is Haileybury College. It was opened in 1809 as a training school for the East India Company. Its architect was the Greek Revivalist William Wilkins, who also designed the National Gallery and University College London. The principal front is stone with three temple front porticos, but the walk passes along the rear where Wilkins' buildings are mostly in yellow brick. The whole is dominated, not to say overwhelmed, by Sir Arthur Blomfield's giant dome, added in 1876 (Haileybury was then a public school). The west arm of the walk follows a stretch of Ermine Street that is a track. Sections of its 'agger' are still visible, and perhaps more evocative of the original Roman road than those stretches that remain as main roads. Named 'Ermine Street' in Anglo-Saxon times, it ran from London to Lincoln, probably by AD 47, within four years of the Roman Conquest.

Walk east along Mount Pleasant and by the Mount Pleasant sign take the left fork along a metalled track.

At the end, by a house, the bridleway bears right on to the wooded heath, then left at a bridleway post. Descend through hornbeam and oak woods, marked by occasional waymarker posts as it becomes a sunken lane. Bear right at the bridleway sign. Cross an access lane, go left and descend alongside the embankment of the A10.

Turn right to go under the A10, turning immediately left up steps to a stile, signposted 'Walnut Tree Walk'. Continue alongside the A10 (for 440yds/402m) to a high, chain-link gate. Go through this to ascend alongside a conifer belt and reach a metalled lane at the crest. Turn right.

At the next road, with the Van Hage Garden Centre on your right, turn left by the Gothic-windowed Amwellbury Lodge. Shortly turn right into Church Path and follow the footpath to Great Amwell.

Cross the lane and pass the George IV pub, then turn right into the churchyard, with its fine monuments. From the churchyard descend some steps, cross a lane and descend further, to the New River – the Myddelton Monument urn island is to your left. Turn right to follow the New River footpath, shortly passing Amwell Marsh Pumping Station.

Leave the New River at the road, turning right, uphill. Past Hillside Lane go left to the restricted byway sign. The track runs between fields, over the A414, and continues to the A1170. Cross this and go over a stile into pasture. Climb to the crest, go over a stile, go across a field, then another stile, and then turn right to descend to the A10 roundabout.

Turn left under the A10, cross to the byway sign and go left up the bank, signposted 'Hertford Heath'. At the top turn right to walk to the right of the woods, now in the grounds of Haileybury College. Continue straight on past the end of the woods on a track.

At a crossroads continue along the tarmac drive, with Haileybury College on your left. The college road merges with the B1197. Turn left at The College Arms, soon with the scrubby heathland of The Roundings on the right. Where the road bears left just before a large white house called Meadow Grange, fork right on to the heath, through trees, to bear left on to a grassy path. Follow this to the road and turn right on to a track.

Now on the Roman Ermine Street, you follow it northwards to merge with the B1197 through Hertford Heath. At the Country Stores shop turn right into Church Hill and back to the green.