Wales
The glacial bowl where Darwin found seashells in the rocks, beneath the Devil's Kitchen.
Charles Darwin came to this hollow in the mountains and found seashells in the rock. Cwm Idwal is a bowl scooped by ice, with a lake on its floor and a black cleft called Twll Du, the Devil's Kitchen, splitting the cliff at the back, and in 1954 it became the first National Nature Reserve in Wales.
The walk in from Ogwen takes minutes, and the circuit of Llyn Idwal is a path most people can manage, which is the valley's gift: a high mountain landscape without a summit to earn. The headwall rises in slabs and ledges, and above the reach of feral goats those ledges carry Snowdon lily, moss campion, alpine lady's mantle and purple saxifrage, arctic plants left behind when the ice went. A harder route climbs steeply towards Twll Du itself; the reserve's guidance is plain that the easier loop avoids it. Darwin's fossils of marine life, found in the rocks of this valley, were part of how he came to read the landscape. Down the road Bethesda is a slate town with a café worth the drive, and the Ogwen Snack Bar at the car park has fed climbers since 1953; leave the car in Bethesda and take the T10 bus up; the national park asks it, and the valley is better for it.
Solo
The lake circuit at first light, then the steep path towards Twll Du if the legs and the weather allow, with a pasty from the snack bar on the way down.
Couple
A gentle loop of the lake in the evening light, the cliffs going pink, and supper in Bethesda.
Friends
Split the group: one half rounds the lake, the other climbs to the Devil's Kitchen, and everyone meets at the Ogwen Snack Bar.
A pasty or a bacon roll from the Ogwen Snack Bar at the valley car park, in one family's hands since 1953 and part of the mountaineering history of the place.
Caffi Blas Lôn Las in Bethesda, the quarry town down the valley, for the proper meal after the walk.

Arenal & La Fortuna
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Drakensberg
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Basalt walls rise above sandstone caves painted across thousands of years.

Parque Nacional Volcán Isluga
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Volcanic horizons and high wetlands surround living Aymara settlements in the altiplano.

Sani Pass
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A switchback road climbs from green foothills to a high border above the clouds.

Blaenau Ffestiniog
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The town that roofed the world, where you bounce on trampolines slung inside a slate cavern.

Harlech
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A castle on a crag waiting for a sea that walked away centuries ago.

Aberdaron
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A church on the sand where pilgrims ate their last meal before the island crossing.

Beddgelert
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A stone village at the meeting of two rivers, named for a legendary dog's grave.