Binntal, the Swiss mineral valley

Fifty-six minerals have this one Alpine valley as their type locality.

More than 300 different mineral species have been found in the Binntal and the directly adjacent sites at Alpe Devero and Alpe Veglia, and around 150 of them come from a single place: the world-famous Lengenbach mineral mine, behind the hamlet of Fäld. For a valley this size those numbers are extraordinary.

The obvious material is quartz. Clear rock crystal and smoky quartz occur here in many different forms, alongside a great many other minerals, most of them small and a good number of them uniquely beautiful.

You will not simply walk up and find them. The park is blunt about this: unlike the flowers and the landscape, which are visible to any hiker, the mineral world here stays hidden under vegetation, rubble and rock, and finding the rarities takes the knowledge and experience of spotters. The park runs guided introductions to crystal hunting for that reason, which is the sensible way in.

The geography is a dead end in the best sense. The Binn Valley lies on the north side of the Lepontine Alps in the Swiss canton of Valais, drained by the Binna, a tributary of the Rhone which it joins at Grengiols. The valley takes its name from Binn at 1,400 metres, the main settlement, with Ausserbinn at 1,291 metres, Heiligkreuz at 1,458 and Fäld at 1,547.

The walls are high. Mountains here generally exceed 3,000 metres, the highest being the Helsenhorn, the Turbhorn and the Ofenhorn. On the upper east side the Albrun Pass crosses into the Italian Valle Devero, which is why the Italian sites at Devero and Veglia keep appearing in the same sentence as the Swiss ones: geologically it is one piece of ground with a border over the top of it.