To find me you must go to the Gloomy Cavern which will make you very sad. In the acrid smoke, you must meet and defeat two dragons with fiery eyes. If you succeed, you will find a hole of toads and snakes. Go down into it, and at the bottom of the hole, you will find a little cave. I am there. The touch of my waters will change age to youth, ugliness to beauty, illness to health, sorrow to joy.

The Fountain of Health and Beauty in The Story of Pretty Goldilocks, Blue Fairy Book