Eldin Spring is a location from The Legend of Zelda: Twilight Princess. Located in Eldin Province, it is home to Eldin, one of the Light Spirits. This is the third Spirit's Spring that Link visits in the game.
Fairies are released to Eldin Spring after the third level of the Cave of Ordeals is completed. A Great Fairy appears here when the whole cave is completed, allowing Link to have a seemingly endless supply of Great Fairy's Tears, provided he has a spare bottle and is not already in possession of a bottle of Great Fairy's Tears.
After bombing a wall near the Eldin Spring, a small tunnel can be found which leads to an open hole above the spring itself. Jumping from it reveals another section of the Eldin Spring that is much deeper. Using the Iron Boots, Link can sink to the bottom where he finds a Treasure Chest containing a Piece of Heart.