Golden Gate Park is 2 times larger than Monaco.
Area: 2 km2 World Factbook
Population: 30,508 (July 2014) World Factbook
Monaco, officially the Principality of Monaco, is a sovereign city-state and microstate, located on the French Riviera in Western Europe. It is bordered by France on three sides; one side borders the Mediterranean Sea. Wikipedia
Area: 4 km2 calculated
Golden Gate Park, located in San Francisco, California, United States, is a large urban park consisting of 1,017 acres of public grounds. Configured as a rectangle, it is similar in shape but 20 percent larger than Central Park in New York, to which it is often compared. Wikipedia