The rapid burgeoning of the free royal town of Banská Štiavnica , and the renown the town enjoyed, were due to its rich ore deposits and the potential for their extraction. The town's significance is suggested not only by the substantial size it had already attained in the Romanesque period, but also by the exuberance of its architecture. The centre of the town - a showcase which includes the town hall and the late-Gothic church of St. Catherine not to mention numerous Gothic / Renaissance town houses - acquired its definitive aspect in the course of the town's fortifications, of which the Piarská brána gate, remodelled in baroque style, still survives. No less a part of the town's heritage are the extensive engineering structures and artefacts associated with the mining and working of polymetalic ores. This includes not only shafts, galleries, pithead gear, bell and a highly sophisticated water supply system integrated into the landscape, but also the buildings associated with the work of the first Mining and Forestry Academy in Europe. Taken as a whole, these attributes were enough to secure Banska Štiavnica and its technological inheritance a place on UNESCO's World Heritage List.