Durdle Door & Lulworth Cove

Come over the brow of the cliff and there it is, one of the most famous sights on the whole coast: a great arch of pale limestone standing out in the sea, the waves passing clean through a hole punched in a wall of rock. This is Durdle Door. A little further along, the land curls inward into an almost perfect circle of a bay, Lulworth Cove, calm and rounded as a scoop taken out of the coast. Together, these two wonders tell the story of how the sea shapes the land.

You are standing at the heart of the Jurassic Coast, England's first natural World Heritage Site, declared by UNESCO in 2001 for cliffs that hold an astonishing hundred and eighty-five million years of the Earth's history. Here the coast is built of alternating bands of hard and soft rock, and the whole drama depends on that. Durdle Door is cut through a near-vertical wall of hard Portland limestone that runs along the shore; the sea, patient and relentless, found a weakness and bored straight through it to make the arch. Lulworth Cove tells the second half of the same story. There the sea broke through the same hard wall at a single point, then spread out behind it and scoured away the soft clays inland, hollowing out that round, sheltered bay until the harder rock at its mouth held the sea to a narrow gate. Geologists and visitors have come here for centuries to read this lesson, because nowhere shows it more clearly. This land is part of the Lulworth Estate, and the Coast Path climbs the cliffs right past both marvels.

Look first at Durdle Door itself, the arch framing a circle of open sea, best seen from the cliff path above and from the shingle beach below. Look second at Lulworth Cove, and if you can gain a little height, take in the near-perfect ring of the bay and its narrow entrance. Look third at the cliffs on either side, where the beds of rock have been bent and buckled: watch for the Lulworth Crumple, a place where the ancient layers are folded like a rumpled blanket by the immense forces that once squeezed this coast. Look fourth at the grassland along the cliff tops, chalk and limestone turf that in summer holds rare butterflies and wildflowers, and at the ledges where seabirds nest. And look fifth into the clear water of the cove itself, sheltered and calm, alive with marine life on a still day.

The real story here is written in the rock, and it is a story of time. Every layer in these cliffs was once mud or sand or shell on the floor of a warm sea, laid down through ages so long that the number barely means anything: a hundred and eighty-five million years. The arch of Durdle Door and the ring of Lulworth Cove are only the latest sentences in that book, carved in the last blink of geological time as the sea works its slow way through hard rock and soft. Stand here and you are watching the Earth at work, mid-sentence, the waves still passing through the door, the cove still slowly widening.

A word of care, for this coast is wilder than its beauty suggests. The cliffs are steep and in places unstable, so keep well back from the edges above and from the crumbling faces below, and never climb them. The currents around the arch can be strong, so take real care near or in the water, and always check the tide before you go down. This place is busiest in high summer, so come early or late if you can, for the quiet as much as the safety.

From here the Coast Path presses on east towards the ranges and coves beyond Lulworth. Take a last look through the great stone door at the open sea, and let it show you, one wave at a time, exactly how it works. Walk safe.