Kalkalpen

Kalkalpen, declared in 1997, is Austria's forest park: 208 square kilometres over the Sengsengebirge and the Reichraminger Hintergebirge in Upper Austria, four-fifths of it wooded — the largest closed forest wilderness in the country, and its biggest roadless area. The rock is limestone and does limestone things: more than eight hundred springs, streams that sink and resurface, gorges the log-drivers once flushed timber down. The summit line is modest — Hoher Nock tops out at 1,963 metres — and the emptiness immodest: no road crosses the park, and whole valleys see more chamois than people.

The beech is the point. When commercial forestry stopped, the mountain woods began growing back toward what they had been, and in 2017 the park's oldest stands were inscribed — together with the Rothwald primeval forest on the Dürrenstein — in UNESCO's transnational World Heritage of ancient beech forests, Austria's only natural World Heritage. The deadwood economy runs rich: white-backed woodpeckers, the blue Rosalia longhorn beetle, some 1,500 beetle species counted with dozens of old-growth relicts among them. And since releases in 2011–2013 this is lynx ground again — a handful of camera-trapped cats that are the species' fragile foothold in the Austrian Alps.

The human layer is, oddly, industrial: for centuries these woods fed the Eisenwurzen iron country with charcoal and timber, flushed down the Reichramingbach through splash dams whose masonry still stands. When the forest railway shut in 1971 its bed became the way in — the Hintergebirgsradweg cycles through rock tunnels into valleys no car has ever reached, past alm clearings like Ebenforst and Feichtau that keep their huts and their views.

What's worth knowing before you go

Molln, with the national park centre, and Reichraming are the gates on the Steyr valley side, Windischgarsten the southern one; buses run from Steyr, and the bicycle is the honest vehicle for the Hintergebirge. The season is long for a mountain park, though the karst plateaus hold snow into May; the payoff months are September and October, when the beech turns and the deer rut echoes off the Sengsengebirge. Come knowing the views are of trees, not glaciers — this is the connoisseur's Austrian park to begin with.

The detail worth the detour is the Große Klause deep in the Hintergebirge: the last great log-drivers' dam, where the Reichramingbach pools glass-green behind nineteenth-century masonry a day's ride from any road.