I wanted to circle back and report some of my experiences with these sites. First, most of the tour buses have very steep steps - more challenging than some of the actual tours, as I have difficulty lifting my left foot high enough.
Troy was wonderful, and although there was a fair distance to cover, and quite a lot of stairs, the steps were a reasonable height, uniform, and all had hand rails. It was tiring, but doable, and completely worth it.
We were lucky to have a completely dry day for Ephesus. Some of the people in our group found it difficult immediately and went back to the bus. Others probably should have. The uneven downhill paths were not really suitable for rolling walkers, and people using those needed a lot of help from their companions. I relied a great deal on my husband's steady arm. One man who walked with a cane was on his own - his wife had been one who went back to the bus at the start - and slipped, fell, and hit his head, and had to be taken away in an ambulance. I think if it had been wet, I wouldn't have been able to manage. As it was, I feel like I didn't see as much as I wanted to because I had to mind my feet so carefully. Everything I did see was amazing. Amazing.
For Epidaurus and Mycenae, it was cold, with heavy rain mixed with a little snow, and strong winds. There were "just two or three steps" down to the museum at Epidaurus (then 2 or 3 more, and 2 or 3 more) but they were rather high, irregular but slippery stones with no hand rail. The path up to the ruins was awkward and I wimped out. The dirt path down to the WC was too difficult for a woman with a rolling walker. At Mycenae, the stone ramp down to the museum was too steep and slippery for me, given the weather. I was so disheartened I failed to see that the path to the actual theater was much more manageable and went back to the bus. This was a failure on the part of our guide (okay, and me) more than an issue with the accessibility of the site.
At the Acropolis, there were long stair-free detours to get to the entrance, where the restrooms had very low toilets that I would not have been able to get up from if I had sat on them (plus no seats, so really required hovering) and the handicapped stalls were kept locked. Once through the entrance, there are golf carts to take you to the elevator. You need the permission of the gate agent to use it, and although my stick was apparently good enough evidence of need, the two asthmatic women with me were a harder sell. On top, everything is easy to access, except the toilets, which are down a fairly long, steep ramp. I don't know if those were any more usable once you got down there. WCs aside, everything was quite accessible, and so worth seeing. XOX from Saturn.