Possibly the most beautiful cathedral in the US. The Cathedral Basilica of St. John the Baptist is the mother church of the Roman Catholic Diocese of Savannah. It is stunning both inside and out and full of history.
The third oldest Jewish Congregation in the US, established in 1735.
Savannah is a very pedestrian friendly and walkable city. While you are walking around be sure to stop through some (or all) of the historic squares and learn a little about the history of Savannah and Georgia. The link will take you to a page that lists all the squares and tells you a little tidbit about each one.
No trip to Savannah is complete without a stroll down River Street!! Linked is a 'Guide to Exploring River Street' to give you some ideas but *make sure* you wear flat shoes or wedges as most of the road on River Street is made of cobblestone!