The node in the ancient place is what powers the stone pillars there. The room’s own lore says the pillars are fed by direct taps to the node nearby.
Where it is
An ancient place, its origin forgotten. The marked map is on the location page: An ancient place, its origin forgotten.
Getting it
Nothing special. Reach the node and use it.
Melding
Stand within three squares of the node and use it. The bond raises your maximum mana by three points plus one for every ten points of Mysticism above five, so between three and eight depending on how mystical you are. You can bond with each node once, and the game will list the ones you hold if you ask.