Limestone promontories, dense forests and a powerful liqueur are the signature features of this 767-sq-km regional park. The 1300km of marked walking trails are a major incentive to visit, but the namesake liqueur is an even bigger draw. The Caves de la Chartreuse introduce the history of monk-made Chartreuse liqueur (including tastings); 24km east is the Musée de la Grande Chartreuse, delving into the monks' secretive lives.
It’s simplest to have private transport to reach and explore the park.
Otherwise, Transisère (www.transisere.fr) runs irregular buses between Grenoble and St-Pierre-de-Chartreuse (line 7000, €5.60, 1¼ hours) and between Chambéry to Voiron (line 7010, €5.60, 1½ hours).