The Purbeck Hills
John Chaffey looks at one of the defining features of Dorset
Published in January ’16
The Purbeck Hills are one of the finest landscape features in Dorset. They extend from the much eroded Handfast Point (or The Foreland) in the east for some fifteen miles to the cliffs of Cow Corner and the lonely cove of Arish Mell in the west. These chalk hills are not a continuous ridge, but are broken by the gap at Ulwell and the twin gaps at Corfe Castle.
Seen from a distance these surging blue hills owe their character to the rounded outlines that billow between the gaps. Their highest points are Godlingston Hill in the east, and Ridgeway Hill in the west, the latter rising from the two cols at Cocknowle to the east and Lutton to the west. Rarely do the hills display the open sheep-nibbled downland of the past, for much of the ridge is enclosed by recently erected barbed wire, supplementing the older gorse and bramble hedges that surround some of the skyline fields. Everywhere the crest of the hills is bare
of woodland, which only appears along much of the sheltered northern slopes of the Hills as a series of east-west ‘hangers’.
The Purbeck Hills are built of almost vertical chalk, well seen in the cliffs at either end, at Ballard Point and Rings Hill. This chalk forms part of the huge Purbeck monocline or upfold, produced by earth movements nearly twenty million years ago. The chalk was affected by the pressure of folding in these movements, so that for much of the length of the Hills it is not the soft white limestone of the Dorset Downs, but is much harder and often more brittle rock. In places the chalk is broken by strong fractures or faults. The most celebrated of these faults is the well-known Ballard Down Fault, seen in the cliffs to the north of Ballard Point, the origin of which is still imperfectly understood. Inland there are faults at the Ulwell Gap, at Corfe Castle and possibly at Cocknowle. These faults have acted as lines of weakness along which streams have eroded these gaps in the past and continue to do so at Corfe Castle. The chalk has been quarried at many places along the ridge, but only overgrown workings now remain, as at the Church Knowle limekiln, and at Rollington to the east of Corfe Castle.
At the eastern end of the Purbeck Hills, the chalk forms some of the most spectacular cliffs in Purbeck. Here the chalk is particularly susceptible to erosion, since it is almost horizontally bedded, and is broken by well-marked fissures, known as joints. Both bedding and joints act as lines of weakness along which the sea can erode. The result is a suite of erosional features in the chalk seldom better displayed. Erosion along the weaknesses in the chalk produces firstly caves, which when cut right through a headland, create a natural arch. When the natural arch has sufficiently increased in size, its roof will collapse leaving a stack. At Handfast Point erosion has separated No Man’s Land (with its numerous natural arches) from the main chalk area by the gap known as St Lucas’ Leap, the name derived from a greyhound that attempted to leap the gap while hare-coursing, and died on the rock below. It is said that in 1770 a man could creep along the narrow headland path to Old Harry. The stack of Old Harry’s Wife collapsed in 1896, leaving only a stump, and Old Harry (another name for the Devil) will suffer a similar fate. Winter storms in 2014 much altered the profile of No Man’s Land. Other stacks just to the south are known as The Pinnacles, the northern one is Little Pinnacle or Haystack, and the southern one is The Pinnacle.
Immediately inland, the views from the short turf-covered Ballard Down are quite incomparable in Southern England. E M Forster in Howard’s End wrote ‘If one wanted to show a foreigner England, perhaps the wisest course would be to take him to the final section of the Purbeck Hills and stand him on their summit…. Then system after system of our island would roll together under his feet…. This is indeed a bold claim to make, but it carries a great deal of truth in it. Looking eastwards the horizon carries the Isle of Wight, itself almost a microcosm of southern England, with its northern estuary-pierced lowland, its central chalk ridge and its southern chalk heights above Ventnor.
If the eye of the observer swings to the left the urban spread of the Bournemouth conurbation caps the cliffs of Poole Bay, whilst in the background are the dark forested skylines of the New Forest. To the north-west are the distant chalk heights of Cranborne Chase, and closer at hand lie the fragmented remains of Hardy’s Egdon Heath, the Frome water meadows, and the wooded islands of Poole Harbour.
In the central part of Ballard Down, where several paths meet, is the oblong stone block, with the now faint words ‘Rest and Be Thankful’ carved on it. It was set up by a Dr Jardine in 1852, with the date still visible. Overlooking the Ulwell Gap is the granite obelisk, erected originally by George Burt, to celebrate the installation of Swanage’s water supply in 1892. It was feared that it might act as a guide to the Luftwaffe in World War 2, so it was temporarily demolished, but was rebuilt by the Royal Engineers in 1973.
The Ulwell Gap is one of the major breaks in the ridge of the Purbeck Hills. It is the source of a small stream that runs eventually down into Swanage Bay. Joining the Ulwell Gap from the west is the remarkable dry valley, Giant’s Grave Bottom. It is deeply cut into the eastern side of the highest point in the Purbeck Hills, Godlingston Hill. The valley is unusual because of the right-angle bend it makes just before it enters the Ulwell Gap. It is thought that this bend may result from a former spring in the Ulwell Gap migrating westwards along a line of weakness, such as a fault, and then changing its course at the present right angle bend to follow another line of weakness northwards towards Godlingston Hill.
The stretch of the Purbeck Hills between the Ulwell Gap and the twin gaps at Corfe Castle is the one most used by walkers and cyclists. They enjoy splendid views from its crest, both southwards to the Vale of Purbeck and Swanage, and northwards to the now forested heathlands and Poole Harbour. The great treasure of this length of these hills is the collection of barrows on Ailwood Down. There are eighteen barrows altogether, seventeen round barrows, much varied in size, and one long barrow. The Neolithic long barrow stretches east-west, and is built slightly below the crest of the ridge, so that it is ‘skyline visible’ from the south. Ten Bronze Age barrows are sited on the crestline, and the two largest and most impressive barrows closely overlook the long barrow, perhaps deliberately overshadowing the older structure. Smaller rounded barrows lie off the main crest, and are probably of a later age than the ridge-top ones. Ailwood Down is a mystical and entrancing place giving us pause to think of the life and death of the early civilisations that first colonized Purbeck.
Woodlands grace much of the northern slopes of the Purbeck Hills between Ulwell and Corfe Castle. They hide two small dry valleys that run down from Brenscombe Hill northwards, one of them giving access to the Rempstone stone circle just below the ridge. The age of the latter suggests a ready connection with the Bronze Age barrows of Ailwood Down. Farther west the Rollington dry valley once carried an ancient route from Little Woolgarston south of the ridge past Rollington Farm and then northwards as Thrasher’s Lane as it cut through the heathland to the little port that existed on Wych Lake on Poole Harbour.
At Corfe Castle, the Corfe River and the tiny Byle Brook have cut two deep valleys in the chalk ridge, isolating the hillock on which Corfe Castle is built between the two almost gorge-like gaps. This is one of the finest natural defensive sites in the south of England. All of today’s ruined fortifications date from Norman times: the first structures were built by William The Conqueror in 1080, the keep being added in 1105, with further defences surrounding the inner bailey. Expansion developed westwards on the spur overlooking the Corfe Valley, and downslope towards the main entrance gateway and the bridge across the moat. Inevitable repairs became necessary, and the gloriette tower began to take shape in the reign of King John. After the loss of the castle to the Parliamentarians in 1646, The Commons voted for the demolition of the castle, although such was the thoroughness of the original construction that it was never completely destroyed. Today it is the site of numerous open air events from mediaeval military battle scenes to open air theatre and Bank Holiday fairs.
Beyond the gap of the Corfe river with its ruined West Mill (still active until the early twentieth century) West Hill rises majestically and the Hills extend westwards to another break in their continuity at Cocknowle. This is the most mysterious of the gaps in the crest of the Purbeck Hills. The narrow road from Barnston crosses the col, and then dives down into a steep sided valley that heads some distance to the west. Further to the east the valley turns through a sharp angle to leave the gap in an almost gorge-like defile. It is not without its similarities to Giant’s Grave Bottom and the Ulwell Gap.
Westwards the Purbeck Hills rise steadily to their second highest point of Ridgeway Hill. On its northern flank is probably the most spectacular ‘hanger’ of all, Great Wood, with its indigenous beeches and exotic conifers.
In the scrub on its southern edge springtime brings one of Purbeck’s most delightful bluebell fields set off by the yellow of burgeoning gorse and the pink of early campions.
Beyond, Grange Arch, Denis Bond’s 1740 folly, is all pillars and arches, looking down through a gap cut in Great Wood to Creech Grange. The folly is now managed by the National Trust, which ensures that its surrounds are well manicured.
The Ridgeway track surges on westwards to reach Steeple Car Park and then enters the forbidden lands of the Lulworth Ranges, alongside the ridge-top road. It soon passes one of Purbeck’s strangest enigmas, the dank, almost sombre patch of woodland, the only one on the southern flanks of the Purbeck Hills in their entire length. This is ‘estover’ land, where former inhabitants from the valley below were wont to collect firewood, and perhaps timber. Westwards the walkers’ track enters open country. To the south is the western end of the Vale of Purbeck, where the infant Corfe River rises, and west of the North Egliston watershed the stream of the Tyneham gwyle (‘wooded valley’) begins to trickle westwards to Worbarrow Bay. Northwards the view encompasses Purbeck’s western heathland and the huge West Creech ball-clay pit.
The track eventually leads to the western culmination of the Purbeck Hills, Flower’s Barrow. This magnificent Iron Age fort sits prominently above Worbarrow Bay, its southern margin eaten away by landslide and erosion alike. The all-embracing view looks to distant Portland, a sullen grey mass in the western sea. Nearer are the steep flint-riven cliffs of Cow Corner, the collapsing heights of Cockpit Head and the pastel cliffs of Mupe Bay. E M Forster would surely have appreciated this vista too, showing perhaps fewer of the systems of southern England, but offering a panorama of unparalleled beauty at sunset. ◗