Savannah, Georgia is 507 times larger than Vatican.
Area: 0 km2 World Factbook
Population: 842 (July 2014) World Factbook
Vatican City, officially Vatican City State, is one of the last six remaining absolute monarchies whose territory consists of a walled enclave within the city of Rome. It has an area of approximately 44 hectares, and a population of around 840. Wikipedia
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