Few people know that the adit that leads to Hron in the village of Voznica is unique in the world. The Hereditary Adit of Emperor Joseph II, with a length of more than 16 km, was the longest mining work in the world at the time of its completion. It was proclaimed a UNESCO World Heritage Site. Its construction (1782-1878) was extended from originally estimated 30 years to 96. At the beginning, the work progressed by only 70 meters a year. By the end the daily progress was 600 meters. It served to drain the Štiavnica mining district, and is operable to this day.
