Here's a detail-image of the model of Ezekiel's ideal temple (Ezekiel 40 -48) that I blogged about yesterday. It shows the second set of huge gate-complexes guarding the inner court of the temple precincts. You can also see the sanctuary building proper in the center of the image, and the altar of burnt offering (# 28; Ezekiel 43:13-27) in front of it. The miraculous river flowing from the temple to give life to the land (Ezek 47:1) is indicated by # 29.
The chamber marked # 27 in the model contains rooms set apart for the Zadokite priests, like Ezekiel, who keep charge of the altar and make sacrifices, according to Ezekiel's hierarchical view of the priesthood. Opposite it, but hidden behind the inner east gate from this angle, is a similar chamber for another set of priests who keep charge of the temple but do not have altar privileges. In my view, this is the priestly group known as the Ithamarites.
Dr. Kevin Wilson and I had an interesting debate about the Ithamarites and their importance, or lack thereof, in the postexilic period not too long ago. For a sampling of this debate/discussion, click here