I took it once as "research" before friends of mine arrived. Very frustrating, because so many of the streets surrounding the major landmarks are no-cars streets... so the hop on/hop off bus is restricted to very heavy-traffic major streets lined with stores and apt houses... NOT what you are looking for! Waste of Time. Almost all the major highlights are clustered togther except the Natl. Arch. Museum which is straight up a major street, and easy taxi ride for 5-8E. If you want to cut back on your walking, a really good alternatiiv would be the cute little "choo-choo" the athens HAPPY TRAIN -- http://www.athenshappytrain.com it's a truck disguised as a train, with 4-5 open-side cars behind... similar to ones that go on boardwalks. It is allowed to go on the no-car 'streets" and winds all around the major sites. It is hop-on/hop-off, and not a long wait I think, because they come round every 40 minutes or so. Costs I think 5-6E. Could be your answer.