Banska Stiavnica was one of the most important European sources of silver, lead and iron ore from the 13th century onwards. The town and its surrounding landscape with relics of mining and smelting activities have been a World Heritage Site since 1993. New techniques were introduced in mining here earlier than elsewhere: for example, gunpowder was used in a mine in 1627, probably for the second time ever. In order to prevent the mine from closing down due to water inrushes and at the same time to obtain water energy for the poorly supplied town, an elaborate system of water reservoirs and canals, the so-called tajchy, was designed and built, and a complicated pumping system was installed. In 1722, parts of the mine that had become inaccessible due to water ingress were drained using an athmospheric steam engine based on the principle developed by Newcomen, the first 'fire engine' on the European continent.
To this day, the town has many buildings that recall its prosperous past. These include two castles, outstanding Renaissance houses and the Kammerhof, where the ores were tested. The open-air museum of mining, opened in 1974, displays many surface structures from old mines, and includes a 1300 m circuit of underground workings. A 16th century merchant’s house in the town accommodates geological and mineralogical collections, while displays in the castle, Stare Hrad, include historic paintings of the town and an exhibition on the history of metallurgy.