North Wold's geology

Caistor's origins are Roman, its name Castra meaning camp or fortification, and small fragments of the original encircling wall still remain in the vicinity of the church. Ermine Street passed close by, and a short hillside track joined Caistor to the important north–south route from the Humber to the Roman fort of Banovallum (modern-day Horncastle). Caistor town centre has several impressive Georgian houses, but sadly few from earlier times, since a disastrous fire in 1681 burnt down most of the town.

Geology and conservation

Caistor and Nettleton sit at the foot of the sharp western escarpment of the Lincolnshire Wolds, a modest but undulating series of chalk uplands in the county's north east corner, which form the highest land on England's eastern seaboard between Yorkshire and Kent. The high point is Normanby Top, just off the walk, at the dizzying height of 550ft (168m)!

The main rocks of the Wolds – chalk, limestone and sandstone – were laid down during the Cretaceous era around 65 million to 135 million years ago. Overlying sands and gravels came later, during the ice ages of the Pleistocene era, around 1.8 million years ago. Although dominated by a thick band of chalk, the western fringes of the Wolds have deposits of ironstone which was mined during the last century near Nettleton Top. The ore was taken down the hillside and transported by rail to Scunthorpe for smelting. The machinery has disappeared, but the mounds and scars are still evident today.

The high chalk Wolds have poor, thin soils, and are mainly, but not exclusively, grazed by sheep. However, in the south of the Wolds the chalk is covered with deposits of boulder clay, gravel and sand, which give rise to better agricultural soils. Although some villages even had their own brickworks, the chalk has also been quarried for building stone.

The Wolds were designated an Area of Outstanding Natural Beauty in 1973. The Lincolnshire Wolds Countryside Service aims to promote the landscape and its conservation, and improve opportunities for quiet recreation. They produce a regular guide and organise guided walks and events. Visit www.lincswolds.org.uk to find out more.

Walk down the ramp from the car park and cross the road to the Market Place, then continue straight ahead down Plough Hill. At the end continue, swinging right along Nettleton Road. When it becomes Richards Row, look for a footpath along a passageway between houses on the opposite side of the road. Now thread your way left through a small estate, all the time following the Viking helmet waymarks for the Viking Way.

Cross over Caistor bypass and go directly ahead through fields towards Nettleton, veering diagonally left in the last to skirt a modern bungalow. Turn right into the lane below, and walk to the junction in the middle of the village. Go left on Normanby Road. In a little over 0.25 miles (400m), leave the lane for a private drive on the left, indicated 'public bridleway', by a house called Hazeldene.

Follow this route as far as Nettleton Grange, then veer left with the track as it goes through a gate beside the Nev Cole Memorial Stile. On the far side of the gate turn right (the main track goes straight on) and for 0.5 miles (800m) follow a public footpath alongside Nettleton Beck, keeping the stream and ponds on your right. The path, which can be boggy in places, eventually climbs a rough grassy hillside to emerge on a surfaced lane.

Turn left and walk along the lane uphill for 150yds (137m) until a sign points you right for a track into woodland. Follow the undulating path past bricked-up tunnel entrances, the remains of former ironstone workings.

Go through two gates to emerge onto open pasture and a route that again keeps to the left of Nettleton Beck. When the stream disappears into a spring, continue up the shallow valley floor. Turn right at the top on to a farm track (bridleway) and walk along to the lane at the end near Acre House.

Turn right, and follow this pleasant lane, via Nettleton Top, all the way back to the village of Nettleton. There are superb views over the flat plain of North Lincolnshire to South Yorkshire and the Humber, with the towers of the Humber Bridge visible on a clear day and the Yorkshire Wolds beyond. At Nettleton retrace your steps back to Caistor.