322 stairs to the viewing balcony does require a little dedication not to mention some targeted encouragement from ones better half! Well worth it in the long run.
Thanks! Never thought one could climb inside St Peters...
It's part of a Vatican guided tour. The tour starts at 7am and takes you through St Peters and then the Vatican Museum. Takes about 5 hours. 322 steps puts you to the viewing balcony at the top of the dome.