Thermal springs are natural water sources that emit heated water from the Earth's interior. This heat is usually generated by geothermal energy, which comes from the Earth's core. The temperature of the water can vary significantly, often reaching temperatures above 37°C (98.6°F). These springs can be found in various locations around the world, often in volcanic regions. Many thermal springs are rich in minerals, which can provide health benefits and are often used for therapeutic purposes. People visit these springs for relaxation and to enjoy the soothing effects of the warm water. Some famous thermal springs include Yellowstone National Park in the United States and Blue Lagoon in Iceland.