So I was in Jordan in March and did not want to miss this site and hired a driver to take my son and I out to Um er Rasas. The driver was a tour guide and he is out with tourists every day but he confessed that he has not been to this site in the last four years as no one wants to visit it! He took several wrong turns but a local farmer pointed us to the right road.
When we arrived, there is a beautiful brand new visitor's center. However the parking lot was empty as we were the only visitors at that time. Also all the facilities were not open except the rest rooms. The restaurant, visitor's hall, ticket office were all closed. The guard showed us to the back gate which opens to the site.
The previous descriptions are accurate. A whole pile of rocks strewn over a very large area. We walked around for a while taking pictures and then headed to a hangar like structure that covered the mosaics of St Stephen. The mosaics were superb and well worth the visit and the viewing platform allowed a top down view. Later we visited the stylite tower sitting by the road. Unfortunately, it is still being restored with scaffolding. On the other hand, since no one was on site, my son and I climbed the stairs of the scaffolding to the top of the tower and had a great view of the surrounding area from nearly 50 feet up. We also looked into the top cavity to see what its like to sit in there for years and saw a lot of bird eggs.