The Four Hearts of Tharizdun, The Four Hearts of Therafim, The Heart of Ice, The Heart of Flame, The Heart of Stone, The Heart of Wind. Also known simply as The Four Hearts, or The Hearts, it is greatly debated whether the Hearts are free or won. The optimistic or the faithful believe that The Hearts are by free by the will of the gods never to be claimed by anyone, whereas others like I believe that The Hearts are claimed by that master of elements, Tharizdun -each one with a Temple of Elemental Evil built around it to keep their powers for His most high priests. However, there are some that say some Hearts are free and some are not, and that Tharizdun still seeks to control them all.
Vast concentrations of elemental magic have imbued four distinct locations with incredible power. The Hearts of Ice and Flame are abnormally cold or heated wherever they are, and the presence of pure elemental energy is constant. It is believed that these two respectably, are the hottest and coldest places in all the world. The Heart of Stone is a cavern undoubtedly in the Underdark I would say -though a few hold that it exists in The Abyssal Labyrinth, under Panoceana. Lore says one will know it by the fact that abjuration magic is greatly augmented and that the entire area consists of only one kind of rock or earthen material of extraordinary purity, perhaps diamond. The Heart of Air may be an open space at the highest point in existence, on some mountain, in the open sky, or even far beyond in the void between Therafim and her moons. The powers each of them convey are varied- the ability to enhance cold or fire magic, the ability to convert any spell into an adamantine abjuration and,the ability to use any spell limited to touch at great distance. All of these powers may be granted for one year's time with the exception of The Heart of Air, whose power like the wind is fleeting and will last only for one moon.