The Phoenix Park is the largest enclosed urban park in Europe and contains several stately homes, including the official residence of the President of Ireland, Áras an Uachtaráin (the "Irish White House" open on Saturdays), Farmleigh House (open for tours daily) and the US Ambassador’s residence. The Park is also home to the Dublin Zoo (est 1831) and the 22-acre Victorian People’s Flower Gardens (est 1864). Phoenix Park is open to the public all year round. Features to see include the Wellington Testimonial (obelisk, 1861), the Phoenix Monument (1747) and the Papal Cross (1979). Also contained in the park are polo, cricket and hurling grounds; cycling routes and walking routes. The Magazine Fort which dates to 1611 can be visited and offers nice views of the valley below. There is also a prehistoric burial chamber in the park.