


A hot spring is a spring produced by the emergence of geothermally heated groundwater from the top layer of the Earth's ground. Hot springs are in many places, especially in mountains. The water issuing from a hot spring is heated by geothermal energy, i.e., heat from the Earth's mantle.

There is no universally accepted definition of a hot spring. For example, one can find the phrase hot spring defined as
{{cite journal}}: CS1 maint: multiple names: authors list (link) provides a critical discussion of the definition of a hot spring.