No drink has a story like absinthe. It starts in Couvet around 1770 with a homemade remedy, becomes a small distillery in 1798 — Dubied Père & Fils, with a young Henri-Louis Pernod, born at Le Locle, at the stills — and explodes when Pernod opens his own house at Pontarlier in 1805. By 1910 the world drank 36 million litres a year; then panic and prohibition banished it, and for nearly a century the valley distilled in secret —  local pharmacies kept the "medicinal" alcohol flowing to clandestine distillers until the ban was lifted in 2005. The walk threads this story through a landscape of its own time capsule: the forêt jardinée of Couvet, where Biolley replaced clear-cutting with the single-tree selection now studied by foresters from five continents, and whose Président fir grows fifteen centimetres a year at 280 years old. In Môtiers, absinthe meets philosophy: Rousseau lived his exile here from 1762 to 1765, in the same valley that would soon distil the drink of French soldiers and Parisian poets. Ends with a guided tasting in a distillery and optional visit of Maison de l'absinthe.