Bükk karst system continues in great depths towards Alföld (Great Hungarian Plain) where the heat of the Earth warms up the slowly leaking water. This warm water is utilized in the spas in Miskolc which are the most important tourist attractions in the town.
The most well-known spa is the Thermal Bath in Miskolctapolca that is famous for the cave pools. Based on its hydrological and balneological specialities and significance it is a nature reserve from 1982. The temperature of the water is between 27 and 31 °C that arises from Thermal karst spring at the elevation 130 asl.
The one-time, all year operating indoor swimming-pool and vapour-bath were situated in the downtown of Miskolc in Erzsébet square. The tarnished domed building operates as Erzsébet Bath Complex Diagnostic Therapeutic and Health Centre from 1996. Temperature of the arising karst water is about 45 °C; owing to its high sulphide content has intense hydrogen sulphide smell.
The third investigated spa called Augusztus 20 - established in 1927 -is situated in the eastern part of Miskolc, near Tisza Railway Station on the left bank of Szinva creek and shortly became a popular thermal bath. Nowadays it is called Selyemréti Thermal Bath. Two thermal wells supply water for the spa; the water temperature is around 45 °C.
SMARAGD-GSH Ltd. designed the safety plan of the Miskolc Thermal spring and thermal wells in 2013. The protection zones of the Thermal spring and wells constitute a uniform system with the protection zones of the karst springs that provide drinking water supply for Miskolc.