Touring for 3 weeks

Hi. The complexity of planning a schedule, as revealed in the forum, has us thinking of something organised in a tour. We did this recently with a small group in Cuba and loved it as we stayed in houses and saw things away from the crowds. We're not so much into big cities - more so beautiful countryside and adventures, seeing monasteries, taking trains and ferries and staying in inns. Unfortunately our budget is fairly limited, and long walks can be a struggle (being 60ish).Has anyone had a great tour like this they can recommend please?
Thank you for help & suggestions. Tom & Kat

Try G.A.P. Adventures or Intrepid Travel. Their trips are only 14 days but you could then supplement with a week on your own.