Phoenix Park is 2 times larger than Central Park.
Area: 3 km2 calculated
Central Park is an urban park in the New York City borough of Manhattan. It was initially opened in 1857, on 778 acres of city-owned land. In 1858, Frederick Law Olmsted and Calvert Vaux won a design competition to improve and expand the park with a plan they titled the Greensward Plan. Wikipedia
Area: 7 km2 calculated
Phoenix Park is an urban park in Dublin, Ireland, lying 2–4 km west of the city centre, north of the River Liffey. Its 11 km perimeter wall encloses 707 hectares, one of the largest walled city parks in Europe. Wikipedia