Mlýnský pramen, Thermal spring in Karlovy Vary, Czech Republic

Mlýnský spring is the sixth Karlovy Vary mineral spring, located on the left bank of the Teplá River at the southeast end of the Mill Colonnade. Its water rises at 61 °C from a 12.5-metre-deep bore and flows at 4.3 litres per minute into a reddish-brown granite vase set in a semicircular apse. Above the spring hangs a marble plaque from 1500 with Bohuslav Hasištejnský z Lobkovic's Latin ode to the Vřídlo, alongside Jaroslav Vrchlický's Czech translation.

The spring was first documented in the 16th century and took its name from a mill that operated on the Teplá riverbank until the 18th century. The Mill Colonnade that surrounds it today was built in the second half of the 19th century as part of the spa town's development.

The spring's name comes from a mill that stood on the Teplá until the late 18th century. Above the granite vase in the semicircular apse hangs a marble plaque from 1500 with the Latin original of Bohuslav Hasištejnský z Lobkovic's ode to the Vřídlo, and a second plaque carries Jaroslav Vrchlický's Czech translation.

The spring is freely accessible at the southeast end of the Mill Colonnade, on the left bank of the Teplá in the spa centre. The granite vase sits in a semicircular apse of the colonnade, so look for the arcade rather than a separate building. The water is 61 °C, so it is drawn into spa cups rather than drunk straight from the source.

The water contains fluorides and silicic acid, known for centuries for their soothing effects on the stomach. Many visitors drink the warm water directly from special cups available in the drinking hall.