Oku Bahal, also called Rudra Varna Mahavihar, is a working monastery courtyard south of the Mahabouddha temple. It is one of the most photographed of Patan's bahals because of the menagerie of metal objects in its central square: bells, lions, an elephant, a stone Garuda, a peacock. Each is a votive offering left over centuries by craftsmen and patrons.
The monastery has produced bronze-casters for over a thousand years, and the streets immediately around it are still where most of the high-end Buddhist statuary sold in Nepal is actually made. If you are interested in buying a singing bowl or a statue, this is one of the more honest places to do it — many shops here are run by the families that cast the work themselves.