Jurassic Coast Walk: Exploring Lulworth Cove, Durdle Door and White Nothe

Named for its richness in ancient fossils, the Jurassic Coast’s beauty has also been the inspiration for works of fiction and is the real life setting of some old smugglers tales. Mammut sent Cicerone Walking Guides author and Jurassic Coast expert, Ronald Turnbull, along with local outdoor photographer Pete Elliott to explore the towering white cliffs above, the ancient fossils beneath and the secret smuggler routes of the coastal paths - here's how it went.

Just after sunrise on the Dorset coast – a grey early-Spring day, and a cold wind blowing. The fantastic sea-arch of Durdle Door stands against a steely blue sea. But in against the biscuit-coloured beach, the waves are an unlikely turquoise blue. If I saw it in a photograph, I'd think the photographer had been overdoing it a bit in the post-processing. But that explanation won't do for real life… It takes a moment to work out that somewhere around the corner the sea must be rinsing through the debris of a recent rockfall, and re-colouring itself with chalk dust.

The Jurassic Coast is the UK's longest, and third-thinnest, World Heritage Site. Its 154km of coastline offer airy clifftops, grassy downland, and cunning little coves miles from the tarmac road. A waymarked path with National Trail status, part of the 1000km South West Coast Path, runs along it from end to end. Inland, the chalk downland has a network of grassy bridleways, offering the same huge sea views from slightly further away and a hundred metres higher up. Combine coast with downland for an out-and-back that can be any length you like. Today's plan was to cover the coastline's most exhilarating section, the high chalk cliffs between Lulworth Cove and Osmington. The downland, though higher up in elevation, has less up and down than the coast path, so it's the easy bit of the out-and-back walk. The miles slip away on the grassy paths, with the grey sea stretching to the paler grey hump that's the almost-island of Portland low against the sky.

The signboard of the Smugglers' Inn at Osmington is a 20th-century invention. Emmanuel Charles and French Pete, who ran their operation from here in the 1790s, were far too sensible smugglers to give it such an obvious name.

But even when known as The Crown, its low-hanging thatch, oaken beams, and little sunken windows looking straight out to sea, all mean it couldn't possibly be anything else. Emmanuel's brandy, they say, was so harsh and poisonous that no-one from the village would drink the stuff. We play it safe and stick to the beer.

Meanwhile the salt-blistered old sea dog behind the bar passes on legends of the smugglers in a Dorset accent rough enough to strip off barnacles. Except that as this is the 21st century, the person behind the bar is hardly sea-blistered at all as she passes on the legends in the convenient form of seven photocopied A4 sheets. We sit below a poster offering us £500 if we have information leading to the capture of French Pete or his ship…

After lunch we dip to the shoreline below to poke about among the rocks, crammed with sea-shells from the semi-tropical shoreline of 160 million years ago. This is the Jurassic Coast, after all, and the UK's biggest open-air Earth Sciences laboratory. We also take a look out to sea, as the next couple of kilometres of the path will run under scrubby, wind-bitten woodland. And then we emerge onto the shingly Ringstead beach, below its sloping cliff of black shale.

Break this soft stone in your hand and there's a faint smell of paraffin. For this is the Kimmeridge Clay, so rich in oil that the whole cliff face went on fire in 1826 and smouldered away for several years. It's also so rich in ancient life that someone who's not even looking for fossils can get lucky and spot half an ammonite poking out of a boulder.

A few steps on, and there's a seawashed stone with some very interesting Jurassic coral. "Well, now you tell me," says Pete the photographer, "I guess it is coral. But before that, it was just scratches in the rock." He doesn't bother taking a picture of the very interesting coral…

There was a good reason for not lingering in the pub over the story of Frenchman Pete and the teenage exciseman hiding up the chimney (just for a laugh, they decided to light the fire underneath him). For now, with boulders and cliffs blocking the beach line, we have a real smuggler's route to trace, up to the clifftops of White Nothe 150m overhead.

It starts with a wooden set of steps leading up off the beach. And then a small path runs in and out through strange humpy ground, densely covered with bushes and scrub. You can hear nightingales in here in the daytime, the footpath ranger once told me.

One moment we're deep in the bushes, looking at white flowers of the thorn trees, and upwards between them to towers of white chalk against the sky, with a single raven drifting across. A few steps later and we're out in the open, at the top of the low, crumbling beach cliff, looking right across the wide Ringstead Bay.

The crumbling chalk below our toes is, in fact, the same chalk cliff as the one high overhead. A chunk of landscape has simply dropped towards the sea, sliding on the soft Kimmeridge Clay underneath. The hummocky ground between the upper and the lower cliffs, isolated as a natural nature reserve, is a classic example of an undercliff formation.

At its end, the path must find a way up between the upper cliffs. This unlikely route features in Chapter 10 of a Victorian adventure story, Moonfleet by J Meade Falkner. "The Zigzag started off as a fair enough chalk path, but in a few paces narrowed down till it was but a whiter thread against the grey-white cliff-face, and afterwards turned sharply back, crossing a hundred feet direct above our heads... I do not believe that there were half a dozen men in England who would have ventured up that path. The ledge was little more than a foot wide, and ever so little a lean of the body would dash me on the rocks below."

Okay, the thrilling adventure story has hyped it up a bit. The narrow path zigzags up on grass, rather than naked rock. It's easy enough walking, at least in dry conditions. But chalk cliffs rear up on either side, and below the path the grass curves away downwards and then you just see the gently moving English Channel 100 metres below.

In 1822 the Preventative Service caught on to all this, and built a neat row of stone coastguard cottages exactly at the top of the path. A windy place to live, but what great sea views! And the coastguard cottages also hint at why today's national trail so scrupulously crosses every possible one of the clifftop sea views. The Coast Path is no 20th century invention, but was constructed 200 years ago, with officers on horseback riding along it with their telescopes and muskets to intercept the arriving ships.

And so, from here back to Lulworth, the path stays within a few metres of the clifftop all the way. The first time I walked this coast, it was the end stretch of a long hike from the Bristol Channel to Old Harry Rocks at Swanage by way of Cheddar Gorge, the cathedral city of Wells, Sherborne Abbey and the Dorset Downs. This section along the chalk cliffs to Lulworth, and on through the Lulworth firing ranges, struck me not only because of its wide seascapes and sculpted rocks, but also because of being jolly hard work. A series of steep chalk valleys have been sliced right across by the sea, for a coastline path that goes steeply up to a bit of teetering along the brink, then steeply down again, all ready for another steeply up.

On a hot August afternoon, this was as tiring as any Scottish mountain; and the massed cars of Lulworth's car park made a sun-gleaming inland sea to match the real sea on the other side.

But now in early springtime, the one or two beach walkers were in padded jackets rather than bikinis. The wind was chilly and fresh, and the summer car park just a battered green field. Normally I end a walk here at the Lulworth Crumple. No, it's not the moment of thankful relaxation as you collapse into the sand with your end-of-walk ice cream dribbling over your sweaty fingers. It comes about ten minutes before that, a splendidly squashed-up bit of sea cliff, pierced below by a mini-Durdle Door.

But this evening, Pete the photographer leads out of a different corner of the car park to his own favourite endpoint: a place called Dungy Head. It's a grass-topped knob of crumbly limestone, looking back along the coastline we've just been walking over.

Around the curve of the bay, sea-cliffs rise one behind the other: Durdle Door, Swyre Head, Bat's Head with the tiny hole through at sea level; and fading against the sky, the slope of White Nothe displaying the exact steepness of the smugglers' path we came up four hours before. The sun makes a golden streak across the slate-blue sea, and the cliffs gradually fade in the salt haze thrown up by the breakers at their foot.

Peter scurries about finding dangerous looking outcrops to take photos from, at the same time making picturesque shapes himself against the darkening sky. And then it's time to just sit on the grass, through what Pete calls the Blue Hour ("cos yes, you can get some good blue-y ones too"). And watch the pastel shades in the sky, and the sea, and a strange lenticular cloud like a smuggler's cloak over the hump of Portland on the other side.

All right, so the Jurassic Coast may not be the thinnest World Heritage Site. Hadrian's Wall beats it that way, and so does the Pontcysyllte Aqueduct. (Come to think of it, those two are pretty good to ramble along as well.) But when it comes to a grand bit of walking, with a feet-on demonstration of hard science thrown into the mix, there's only two words for it.

Fantastic. And Jurassic.