There are many green-spaces around the city, and Dublin City Council manages over  of parks. Public parks include the Phoenix Park, Herbert Park, St Stephen's Green, Saint Anne's Park and Bull Island. The Phoenix Park is about  west of the city centre, north of the River Liffey. Its  perimeter wall encloses , making it one of the largest walled city parks in Europe. It includes large areas of grassland and tree-lined avenues, and since the 17th century has been home to a herd of wild fallow deer. The residence of the President of Ireland (Áras an Uachtaráin), which was built in 1751, is located in the park. The park is also home to Dublin Zoo, Ashtown Castle, and the official residence of the United States Ambassador. Music concerts are also sometimes held in the park.