One of the landmarks that heralds your approach to Devon as you travel south on the M5 is the Wellington Monument, a strange, triangular obelisk standing 175ft (53.8m) high on the edge of the Blackdown Hills, and particularly impressive when illuminated at night. It's also a great focus for this walk, which starts off through the water-meadows at Culmstock. Once a small market town with a woollen industry, today it lies off the main tourist trail among rolling fields and peaceful beech woods, a couple of miles from the Somerset border. Several farms, such as beautiful Culm Pyne Barton, were recorded in the Domesday Book.

Local hero

The extravagant Wellington monument was erected by local gentry to celebrate the Duke of Wellington's victory at Waterloo in 1815. Earlier military success brought Arthur Wellesley the right to a title: since his family originated from Somerset, he chose the place most closely resembling the family name. He only visited the estate once, in 1819, but local pride was such that his triumphs were publicly celebrated – and in a big way! The foundation stone of the obelisk, on the highest point of the Blackdown Hills (on the Duke's own land), was laid in 1817, but work was spasmodic, and it didn't reach its final form until the late 19th century. The trustees gave the estate to the National Trust in 1934.

The AA distance board here shows how far you can see in all directions. On a clear day you can pick out the Black Mountains in South Wales, 70 miles (113km) north. Prominent at the start and finish of the walk is All Saints Church. The building dates from the 14th century. Beautifully light and airy, it's constructed of local flint, the characteristic pinkish colour of Blackdown chert. The tower is adorned by two ferocious gargoyles and four pinnacles, each topped with a weathervane, erected when the original spire was taken down in 1776. Culmstock's famous yew tree, seen on top of the tower, probably took root at that time – it now has a substantial trunk and, during the drought of 1976, was painstakingly watered by volunteers; perhaps another example of the pride of these Devon/Somerset borderers.

Walk along Fore Street with the church to the left. As it bends right, take the small lane ahead around the church wall. At Cleeve Cottage turn right towards a small gate. Make for the bottom left corner of the field, dropping towards the river, and through a kissing gate.

Turn right and follow the river to cross a stream by a single oak, then go forward to pass through a gate by double ash trees. A wooden footbridge takes you across the river. Bear left, cross the field to a gate, then cross the next field to a gate by stables, and on to a lane. Turn right.

Just past Blackwater Cottage (right), turn left through a gate. Walk straight up the field with the hedge left. When the hedge bears left, aim for the top right corner of the field and a stile. Continue uphill across the next field, aiming to the left of red-brick Pitt Farm. Pass through a white iron gate and walk on to the farm drive. Turn left; where the drive meets a lane, turn right uphill.

The lane becomes a rough track and eventually bears left; a few steps round the corner turn right through a small gate and climb up to the trig point on Culmstock Beacon. Follow the left edge of the ridge on a track. Your destination is the communications tower ahead; the track eventually leads into a broad grassy ride, which curves sharp right. When almost level with the tower (left) bear left across heather towards woods.

Pass through a metal gate into beech woods, and take the broad track ahead. The path eventually leaves the trees and runs downhill to join a tarmac road; carry straight on to meet a larger road on a sharp bend, and continue straight ahead.

When the road curves right turn left over a stile as signed and up the field; pass over two stiles, then a third in the top corner to gain the monument. Turn right down the approach track to meet the road and turn right again.

Where the road bends right take the footpath signed left over a stile. Cross the field and the next stile on to a broad grassy ride (often muddy). Cross the next two stiles and a field to enter a woodland by a stile. Emerge over another stile, carry straight on and over two more stiles to meet the lane. Turn right.

After 250yds (229m) turn right downhill, then right at the first junction. Go straight ahead through the hamlet of Whitehall and follow the lane to Blackwater Cottage, the house passed earlier in the walk. Turn left past the house and retrace your steps home.