St. Tammany Parish, Louisiana is 13 times larger than Savannah, Georgia.
Area: 223 km2 calculated
Savannah is the oldest city in the U.S. state of Georgia and the county seat of Chatham County. Established in 1733, the city of Savannah became the British colonial capital of the Province of Georgia and later the first state capital of Georgia. Wikipedia
Area: 2,885 km2 calculated
St. Tammany Parish is a parish located in the U.S. state of Louisiana. As of the 2010 census. The parish seat is Covington. St. Tammany Parish is one of the fastest-growing parishes in the state, along with Livingston and Ascension. Most new residents are thought to have come from St. Wikipedia