Gambia is 57,984 times larger than Boston Common.
Area: 11,295 km2 World Factbook
Population: 1,925,527 (July 2014) World Factbook
The Gambia is a country in West Africa. It is surrounded by Senegal, apart from a short strip of Atlantic coastline at its western end. It is the smallest country on mainland Africa. Wikipedia
Area: 0 km2 calculated
Boston Common is a central public park in Boston, Massachusetts. It is sometimes erroneously referred to as the "Boston Commons". Dating from 1634, it is the oldest city park in the United States. Wikipedia