We took this tour. Do it if you can. I scheduled our reservation on-line and requested English. They asked me what time I wanted--and when we got there, we discovered they had extended it to others wanting an English tour. One woman wore heels. Not a good idea! It was also a misty, rainy evening so I was glad I was wearing my hiking shoes.
It is amazing to walk on the roof (literally, you are walking on the roof which is granite and "stepped") and to see the city from a totally different perspective. Our guide was very informative and funny. I cannot imagine a family (the bell ringer who was also the canons' personal tailor) living on the roof with his children and chickens but there you have it! You also can view the Cathedral from above the Jesse Tree, peak into the windows and look down into the nave, and see the sculptures more clearly.
