This stage starts at Hauenstein-Ifenthal, a "double commune" on the southern declivity of the Solothurn Jura. In Roman times, this pass was an important transit route between Augusta Raurica and the Mittelland. Nowadays, together with the Isebähnli restaurant near Trimbach, it is more or less regarded as a place of pilgrimage for motorcyclists. Leave the pass road and walk past farms with manicured gardens; then the path plunges into the forest near Kesselberg mountain. On the Challhöchi pass, old concrete blocks, tank traps and a bunker recall the days of "Fortress Switzerland" in both world wars. A little further on: General Wille's house with sweeping views of Gösgen and the Mittelland.

At Chambersberg, you can already see the Belchenflue peak: it is now less than an hour's walk away. The Belchen South Trail, a well-maintained hiking path, once served as the backbone of the fortifications erected in the first world war. Coats of arms etched into the stone still recall the importance of the Hauenstein fortifications. It's worth taking a detour to Belchenflue mountain for the views of the Mittelland and the country around Basel. Walk down via Gwidemhöchi and Wuesthöchi to reach Bärenwil hamlet. As the hiking route passes through the village centre, it branches off to join the forest road. A little later, you will already be on a path that takes you to the forest clearing known as Stelli. Far-reaching views of the Mittelland open up from here. You then follow the path across the splendid meadows on Schlosshöchi hill. To the right, you can make out the ruins of Alt-Bechburg Castle, and a little later you come to Holderbank village. After Wishöchi hill, you'll sweat as you tackle the final section to the summit of the Roggenschnarz. Hundreds of steps take you higher and higher to the very top.

Then comes a fairly long section through the Jura beech forest, at 600-900 meters above sea level. Typical features: neat stands of beech trees that often make you feel as if you are indoors! At Roggenflue mountain, a view unfolds of the entire Mittelland and even the highest peaks in the Swiss Jura: Mont Tendre and Dole. The descent to Balsthal is steep. To the north, above the Mümliswil gorge, you can see the ruins of Neu Falkenstein Castle which was built in the first half of the 12th century. Walk past the old paper factory (which you cannot miss) to reach the end of this stage at Balsthal rail station.