Ashtown Castle (Irish: Caisleán Bhaile an Ásaighis) is a tower house and located in Phoenix Park, Dublin, Ireland (Irish: Páirc an Fhionnuisce, Baile Átha Cliath, Éire). is thought to date from about the 1430's. It was discovered in the 1970's when the building enclosing it was being demolished. The tower is three stories high and constructed of limestone rubble masonry. It has a square turret on the south-east side and a gable and surmounted by a chimney at the east side. Around 1760 the castle was incorporated into a larger Georgian house known as Ashtown Lodge; subsequently demolished.
Pheonix Park Visitors Centre adjoins the castle and gives an historical account of the park from 3500BC onwards. Phoenix Park is the largest enclosed public park in any capital city in Europe and its name is derived from the Irish word fhionnuisce, meaning clear or still water. The Office of Public Works (OPW) (Irish: Oifig na nOibreacha Poiblí) website has section on the Archaeology of Phoenix Park.
Link and Image: Heritage Ireland Phoenix Park Visitor Centre – Ashtown Castle. Image courtesy of their website.