Aether Well

An either naturally or artificially occuring confluence of Aether that through it's already prodigious cache of magical energy maintains and sometimes even grows the amount of Aether it contains.
These locations and structures are incredibly useful to mages and artificers, and on the larger scale, the advent of industrial magic use. 
If one is careful not to outpace it's own condensing, the well can be a ready made fuel source for an infinite amount of spells and artifacts.