Slovakia is home to the only cold geyser in Europe and one of the eight cold geysers known on Earth - the Herl'any geyser.

An excerpt from the article 37 facts about Slovakia

During drilling to find new thermal springs in Herl'any, near Kosice, in 1875 a cool geyser, unique in these parts of the world, was discovered. Its explosions are caused by the accumulation of gases in deep rock cracks, mainly carbon dioxide, which, after reaching a sufficiently high pressure, eject the water flowing into the hole. The geyser is a natural monument and a great tourist attraction.