Those Greeks loved their mountain views! Hence, there were a lot of uphill walks to temples and monasteries. Depending upon which of the Meteoria monasteries you visit, you may have nearly 150 steps to climb, and the upward path to Delphi is fairly long but not too steep. On the islands churches and monasteries may require a short walk up. The Parthenon is a long uphill climb. But, on all these occasions, slow and easy is the byword. You make many stops to hear about what you are seeing (and catch your breath at the same time). Your P.D. will be watching for those who lag behind, and allow catch-up time. Only you know your limitations, but none of our group missed out on any sights. Wonderful wonderful trip!