Walk - Portland Bill
Walk information provided with help from Natural England. Map reproduced by permission of Ordnance Survey on behalf of HMSO. © Crown copyright and database right 2021. Ordnance Survey Licence number 100022021.
- From the far north-west corner of Portland Bill car park, by the motorbike area, take the small path through the grassland to pick up the South West Coast Path. Turn right and follow the path northwards, inland of the MoD buildings and then heading along the top of the cliffs.
The meeting of tides between Portland Bill and the Shambles sandbank, some three miles to the south east, causes such strong currents that the turbulence can be seen from the shore even on a calm day. As a result, many ships were wrecked as they tried to reach Weymouth or Portland Roads (now Portland Harbour). As early as 1669 a lighthouse was planned here, but it was not until the early eighteenth century that Trinity House finally agreed to shipowners' requests to build it.
At first two lighthouses were built with enclosed lanterns and coal fires, but in 1789 Trinity House instructed Weymouth builder William Johns to remove one tower and replace it with a new one, at a cost of £2000. In 1798 two cannons were installed following Napoleon's threatened invasion. In 1844 a seven-metre white stone obelisk was built on the headland to warn of the shelf of low rock extending 30 metres into the sea. This still stands near the current lighthouse.
New lighthouses were built in 1869 - the higher lighthouse on the western coast and the lower lighthouse on the eastern coast - but 1906 these were decommissioned when the current red-and-white lighthouse was erected. This tower is 41 metres high, 43 metres above the sea at high water. Its light flashes 4 times every 20 seconds. Its fog signal blasts once every 30 seconds and can be heard for 2 nautical miles.
Quarrying in the nineteenth and early twentieth centuries took out a lot of Portland's clifftop grassland around Pulpit rock, and the 300,000 visitors making their way to the tip of the island each year have added to its erosion. Recently portions of the grassland have been enclosed to encourage the rehabitation of the island's special maritime vegetation. As a result the maritime grassland is recovering, and hardy plants such as the pink-flowered thrift and the feathery-leaved wild carrot have started to take hold again. Elsewhere in the short-cropped grass you will see ground-hugging plants such as wild thyme, the yellow beaks of bird's-foot trefoil and even the tiny pink stars of centaury. You are asked to stay on the paths and areas of hard-standing around the lighthouse, to allow these plants to flourish.
The MoD buildings are the Ministry's Magnetic Range, used for simulating the earth's magnetic field and measuring its effect on various test objects. Portland Bill was chosen by the MoD for this because Portland stone is non-magnetic and the site is suitably remote from traffic and electrical disturbance. This means that even very small magnetic fields around equipment can be measured with accuracy.
The Lookout Station is operated by the NCI (National Coastwatch Institution), a voluntary organisation set up in 1994, when two sailors drowned there within sight of the newly-closed Coastguard lookout at Bass Point, on the Lizard. It is open every day throughout the year, apart from Christmas Day and Boxing Day, and visitors are welcome, at the discretion of the duty watchkeeper. Visit the NCI Portland Bill webpage for more information, and a video showing huge waves off Portland Bill during stormy weather.
The field to your right after the lookout station is divided up into numerous narrow strips, known locally as 'lawnsheds'. These are strip lynchets, the remnants of a field system where families had their own strip of land to cultivate. Beyond it is Culverwell, an important archaeological site where evidence has been found of extensive settlement here during the Mesolithic (Middle Stone Age) period, around 6000 BC. This site is situated on the Portland Bill Road and is occasionally open to the public (see the Portland South Walk).
- After the lookout station a number of paths head across the island to your right, marked with Coast Path stones. Take the second, running in front of the Southwell Business Park fence, and follow it to the road.
- Turn right on the road, following it around the left-hand bend to take the public footpath on the right just after the hedge. Going through the first gap in the hedge on your left, follow the right-hand hedge through this field, carrying on along the grassy lane ahead, dropping gently downhill to the road.
- On the road turn left and take the path on the right beside a house and heading towards the sea. Follow the path between quarries to join the South West Coast Path above the shoreline.
- On the Coast Path turn right and follow the path around the edge of the island.
The red-and-white stripes of the Portland Bill lighthouse soon appear above the horizon, as does the white tower of the old lower lighthouse, now a bird observatory and field centre (see the Portland South Walk). For more information check out the observatory's website.
The cliffs have been extensively quarried, like the rest of Portland (see the Around Portland Walk), leaving artificial ledges and terraces along the length of the coastline, as well as the remains of cranes used for loading the Portland stone onto barges and the tramways and rail track that brought them here. The rock is seamed with holes and caves, where the sea has eaten into cracks in the rock (see below). Beside the Red Crane, near the southern end of the path, the sea cave with a great overhang is a blowhole in stormy weather, when at certain states of the tide giant waves build up enormous pressure in the cave, and a dramatic geyser explodes into the air with a massive roar.
Between here and the centre of the island there is a raised beach, about 12,500 years old, formed when sea levels rose at the end of the last Ice Age and then fell again, leaving the old beach stranded above the new shoreline.
- Carry on ahead along the Coast Path to return to Portland Bill and the car park at the start of the walk.
On the coastal ledges near the Bill, one of only two seabird colonies in Dorset is home to nesting guillemots, razorbills and kittiwakes.
Pulpit Rock is the last remnant of a natural rock arch, formed by the pounding of the sea, which opened up a small crack in the rock and then washed around the cave this created. Over time the force of the waves caused such a build-up of pressure in the cave at certain states of the tide that the roof fell in, leaving an arch of rock. Now the pounding of the same waves is eating away at the archway, reducing it to a pillar, known as a 'stack'. Eventually the stack, too, will disappear.
At Portland Bill