“What is the Indulgence one earns for visiting? At least a Plenary, I presume.”
For heaven’s sake, Catholics looking for reward for visiting disgraceful papal summer palace?
Shouldn’t Catholic clergy teach how to seek God who is immanent in us and omnipresent in this universe with love of God in one’s heart instead pedaling the indulgences Vatican prelates dreamed up? 
Catholic Institution runs Catholic religion with the faithful rely on clergies handouts let alone the truth whether it will do what clergies claim to do?  
Isn’t it about time to let go of this superstitious indulgences?   LOL