This is my take on the Well of Dragons complex from Rise of Tiamat.
I've re-jigged it on the assumption that the main camp is outside, with only senior people being housed inside, along with prisoners and the treasure store. By the time the PCs arrive the complex is nearly empty, with key resources being in the Temple of Tiamat.
The DM notes draw on the published resource, and have matching numbers where applicable, but are tweaked to suit my campaign.