Hands down the most popular site in the area, this monastery of stunning beauty is in an equally stunning canyon setting. The brick-red cliffs opposite the beige stones of the monastery offer an unforgettable contrast, as does the climb up the stone steps jutting out of one of the churches, to a second story church on top of the one on the first story. The carvings are also very worthwhile, and the monastery has excellent facilities and maybe food for visitors as well.
If you want to see where silk road traders laid their weary heads a thousand years ago, head up the winding road to Selim Caravanserai. You can see the entrance/bar area, and the large cavernous room the guests would share with each other, and their animals. The room has convenient troughs for the animals to eat and drink from!
Mozrov and Arjeri Caves
These rough caves, found very close to one another, were mapped during Soviet times, but there are no markers, no lights, no facilities, no decent road to them. Not many people know them well either, so finding a guide may be tough, but definitely necessary. Mozrov is only 700m long, but has the nicer formations. Arjeri cave, meaning bears cave, is a very extensive cave system, with some good formations, small pools of water, and both have bats.
Yeghegis Village sites
This village, beautifully sited in the canyon below Smbataberd which may be better accessed from the opposite side of the canyon has the very unusual triangular shaped Zorats Church, where the congregation is meant to stand outdoors. It also has another nice small church and much rougher one, and ancient Jewish cemetery across the river below, and don't be surprised to stumble upon women baking lavash in the traditional underground tonir over!
Smaller sites if you have the time or are in the area.
Jrovank - a small cave with water seeping through and a little chapel set up inside.
Magili Cave - another cave system, in the canyon leading to Noravank. Deep system, but few formations.
Areni Church - overlooking the village, this nearly thousand year old small church has been immaculately restored.
Khotakenats Vank Monastery - an interesting little monastery in Khachik Village, overlooking Nakhichevan.
Martiros rock-cut church - a small and simple church carved into the stone mountain above Martiros Village.
Arkazi S. Khach Church - very near Tanahati Monastery, plain church said to have a piece of the true cross buried in its walls.
Moz archaeological site