Trevone and Gunver Head

Go for a walk at Gunver Head and you'll see spectacular geology at every turn. Cornwall is at the cutting edge of coastal geology in more ways than one. The county's coastline is where erosion by sea and weather and by simple gravity holds sway. Together these forces of nature have exposed the geological lie of the land to show us what the ground beneath our feet is made of.

Golden sand

The walk starts at Trevone Bay, one of those lovely punctuation marks in North Cornwall's otherwise endless wall of sea cliffs. Here, land and sea meet gently at a broad apron of tide-washed golden sand, ideal for all beach activities including surfing. The beach gets very busy at the height of summer, but is less popular in the quieter periods of the year. From the beach at Trevone the walk leads inland along lanes and farm tracks past the hamlet of Crugmeer. Beyond here the coast is reached at Gunver Head, where some serious geology begins. Giant pinnacles and tottering lumps of rock are made up of masses of shale shot through with myriad complexities – the end products of cataclysmic earth movements millions of years ago. What we see, in fact, are the wasted and eroded roots of mountains that were formed during vast earth movements that took place long before humans walked on earth. These fantastic giant chess pieces are easily viewed from the cliff path.

Fantastic formations

The Meropes are a sequence of offshore islands and rocky stacks that lie a mere stone's throw from the mainland beyond a narrow rocky channel known as Tregudda Gorge. The most distinctive of the stacks is Middle Merope, a slender offshore tower of earth and rock that culminates in a narrow flat-topped pinnacle. Further south is the feature known as Porthmissen Bridge, a huge grass-topped bulwark which is linked to the mainland by a very narrow ridge of rock, earth and grass and is pierced by an archway at sea level. Further south again is the Marble Cliff on which more than 140 parallel bands of shale and limestone create a fascinating pattern. However, the area's remarkable geology is not finished yet. Keep to the cliff-edge path that leads back towards Trevone and you'll reach Roundhole Point, a sunny little headland of tan-coloured dolerite rock. Just a few yards inland from the point is the spectacular Round Hole, a huge circular pit more than 80ft (25m) deep, caused by the sea effectively tunnelling into the base of the cliff and undermining the soft ground above until it collapsed.

Go down steps at the cafe end of the car park, to the left of the cafe entrance. Turn left and follow a lane that bends right above the beach. Keep to this lane as it rises uphill.

Stay on the lane where it levels off at a junction with a track to the left. Go through a gapway and continue along the surfaced lane through open fields to the little hamlet of Crugmeer.

Turn left at Crugmeer and follow a narrow lane towards the coast. Follow the road round to the right, to a small parking area.

Pass another small parking area in about 30yds (27m) and in a few paces go left down a short overgrown path and cross a wooden stile into a field. (If the footpath is impassable, head back 30yds (27m), go through a kissing gate and bear half right along a grassy track to the field wall where you'll join the route again.) Follow the right-hand edge of the field to reach a junction with the coast path. Turn left and follow the coast path round Gunver Head.

Follow the path steeply downhill into the bottom of a narrow valley, cross a stile and a stream, and continue less steeply uphill. There are dramatic views back to Lower Merope Island and Middle Merope.

Continue along the coast path and cross a high slate stile. Now follow a broad grassy track, well inland from the cliff edge. Soon reach a gravelly track, and several paces ahead bear off right along a grassy path. Skirt round some herringbone-patterned walls. Porthmissen Bridge is visible to the right.

Keep to the right and follow the coast path to the rocky headland of Round Hole Point, where there are picnic spots below the path. Just inland from the Point is the famous Round Hole. Take great care if looking down from the edges of the hole.

Continue along the coast path. Cross a stone stile and reach concrete steps leading down to the lane at Trevone Beach. Turn right, cross above the beach and return to the car park.