When you go beneath cathedrals you think catacombs of once sort of another. While St Pierre does have one, unknown but revered resident, the site is a stunning display of the foundations of the cathedral from Roman times. The modern day engineering is truly impressive and you quickly forget that there are thousands of tonnes of stone above your head.
Imaginatively laid out, the museum takes you through the evolution of the cathedral from pre modern times to the present. The audio guide is informative and to the point, supplemented with three video locations where various subjects are visited in more detail.
The visit improved my knowledge of Geneva many fold so this is a must for anybody who wishes to be better informed about where they live. Allow at least one hour for the visit.
Be sure to buy the combined Musee de la Reformation and Archeological entry ticket.