My first real Age (which I'll begin when two conditions are met: the new plugin is documented and I have time to concentrate on Age building), will be inspired by this great concept art I found, called "fallen beauty".
The entire Age will be inside the ruined structure, exterior trees will be for atmosphere only, much like those in Jalak.
The atmosphere I'd like to aim for will be pretty much the same as in Book of D'ni, part four, when the explorers from D'ni link to the abandoned temple in Terahnee.