What is the importance of Porto Sant'Andrea in the novel, A Thread of Grace?

Porto Sant'Andrea is a fictional small town on the Ligurian coast in the northern part of Italy where most of the characters in this story have lived for a period of time. It is the town where Iacopo Soncini is a rabbi and Osvaldo Tomitz a priest and secretary to the local bishop. It is also where the hotel is where the Brosslers and Blums and Leonis stayed before fleeing to the mountains.