The gymnasium-bath house complex covered 23.000 square metres. It’s built in the “Imperial Style”, implying that it is symmetrical along one axis, with at one end a central hot house (caldarium). It is supposed to have been completed in the middle of the second century AD . It has been repaired and modified through the following centuries, until it was abandoned following the Sassanid invasion in 616.
This is looking straight up to the top of the main entrance.