The Phoenix Park is the largest enclosed public park in any capital city in Europe.
It was originally formed as a royal hunting Park in the 1660s and opened to the public in 1747. A large herd of fallow deer still remain to this day. The Park is also home to the Zoological Gardens, Áras an Uachtaráin, and Victorian flower gardens The Phoenix Park is only a mile and a half from O’Connell Street. Both passive and active recreational pursuits may be viewed or pursued such as walking, running, polo, cricket, hurling, and many more. The Glen Pond is set in very scenic surrounds in the Furry Glen. There are many walks and cycle trails available to the public.
http://www.phoenixpark.ie