Shooting its scalding water to a height of some 40 feet, the Vřídlo is indeed Karlovy Vary's hottest and most dramatic gusher. Built around it is the jarringly modern Vřídlo Colonnade. Walk inside the arcade to watch patients take the famed Karlsbad drinking cure. The waters, which range from 30°F to 72°F, are said to be especially effective against diseases of the digestive and urinary tracts. They're also good for gout (which probably explains the spa's former popularity with royals). If you want to join the crowds and take a sip, you can buy your own spouted cup from one of the souvenir vendors throughout the town.
Vřídelní ul., near Kosterní nám., Karlovy Vary, Bohemia, 360 01, Czech Republic