Well of Elements

The Well of Elements, or the "Elemental Well'', was a structure within Skya Nui that provided power and light to the floating continent. The Well was created by the Great Beings to provide a source of Toa Power for their creations and was the source of the first Toa Stones.

Early History
The Well of Elements was created some 100,000 years before the Great Cataclysm within the body of the Great Spirit Mata Nui. The well was placed within its own self-contained pocket dimension so that it's power would not kill or maim anyone around it.

Once completed, the Great Beings built the spherical shell of the continent known as Skya Nui around the Well, and then used the Well itself to power the inner surface's artificial sun.

Near the completion of the Matoran Universe, the Great Beings harnessed the Well's energy using the Kanohi Ultima and used it to create the first Toa, Helryx, and manufacture the first Toa Stones.

Apperance
From the outside, the Elemental Well appears like a star that brightens and dims in the sky above Skya Nui. The star can be accessed by one of three support pillars, which provide entry into the Well's pocket dimension.

Inside the pocket dimension, the Well appears as a field of energy surrounded by a strange, technologically advanced environment. Toa Power and Elemental Energy radiate throughout this area, and the Well itself is only accessible from a path that shifts according to power fluctuations within the realm.

Phenomena
The Well of Elements can create several strange and seemingly impossible phenomena. It has already physically effected Skya Nui's surface, imbuing patches of stones with latent Toa Power. These naturally occurring Toa Stones cannot, however, be used to create new Toa, although many Matoran have turned the glowing rocks into jewelry and light sources. The Well can create lightstones as well.

Another, more terrifying note is the fact that the Well will actually feed off beings' Elemental Energy when someone imbued with it comes near. It is believed that this may be the result of the Well attempting to regain power that was taken from it, or possibly as a defense mechanism in order to prevent hostile elemental power users from taking its power for themselves.