Above the watchmaking towns of Grenchen and Bettlach, the first chain of the Jura rises like a wall out of the Aare plain, and on its steep southern flank grows the beech forest of the Bettlachstock. In 2021 it became one of the Swiss components of the UNESCO Ancient and Primeval Beech Forests of the Carpathians and Other Regions of Europe, a serial site that stretches across the continent to show how beech spread after the last Ice Age. What makes this patch special is that it has been left largely to itself for decades, on slopes so steep and rocky that nobody bothered to log them hard, and so the trees grow old, fall, rot and feed the next generation.
You feel the geology as soon as you leave the valley. The Jura here is folded limestone, pale and fractured, and the roads climbing toward the Grenchenberg and the high pastures are narrow, steep and full of tight bends, with gradients that keep you in first and second gear. Surfaces are generally sound, but expect gravel at the edges, cows on the upper stretches and walkers on weekends. Looking back, the view opens over the Aare plain to the whole Alpine chain from the Säntis to the Bernese giants, best in the clear air of autumn mornings when fog fills the lowlands below you.
The forest itself smells of damp leaves and wild garlic in spring, and in high summer it stays cool even when the plain bakes. Woodpeckers, including the big black species, work the dead trunks, and the understory is full of ferns and orchids on the lime soil. Please treat it as a reserve: park where parking is marked and walk in, rather than trying to find a track.
Grenchen, just below, is a town of about sixteen thousand with fuel, food and a long industrial history built on watch movements, and it also has a small airfield whose gliders often hang over the ridge on thermal days. Solothurn, the baroque little capital with its eleven churches and fountains, is a short ride east and makes a fine lunch stop. The upper farms on the ridge sometimes serve simple food in summer, but do not count on it; bring water and tank up before you start climbing.