The mining tunnel "Starý Martin" (“Old Martin”) was among the most important mines in the Krupka district. From the fourteenth century until well into the 1930s, mining was carried out here in one of the richest and longest tin ore veins. Today a visitors’ mine with an open-air museum vividly conveys information about the various methods of extracting ore as well as mining in the past and present. The presentation is enhanced by a collection of historical objects, an overview of the coats of arms of all Bohemian mining towns, and an exhibition of minerals and rocks. The so-called “Glücksquelle” (“Source of Happiness”) with its stalactites is particularly well worth a visit. The guided tour of the one-kilometre route takes about forty-five minutes. There is a large car park for visitors immediately opposite the mine.