Ashtown Castle, Medieval tower house in Phoenix Park, Dublin, Ireland

Ashtown Castle is a four-storey tower house of rough grey and brown stone blocks, with a smaller, higher tower attached at one corner. Its main facade has small rectangular windows with stone surrounds and an arched wooden door at the base of the tower. A row of small stone openings runs beneath the roofline of the gabled, stone-edged roof.

Construction began in 1430 when the government supported the building of defensive structures across the region with financial assistance. Over the centuries, the tower was eventually enclosed within the walls of Ashtown Lodge, concealing it from view.

Ashtown Castle is known in Irish as Caisleán Bhaile an Ásaigh, and it now stands beside the Phoenix Park Visitor Centre, which holds an exhibition on the park's history from 3500 BC to the present. Visitors can see the tower house and then cross to the centre, where a café sits in the grounds.

Ashtown Castle is reached through the Phoenix Park Visitor Centre beside it, where visitor information and a café are available. The tower interior is seen on guided access; ask at the centre desk for the current arrangement before climbing the four floors.

The tower was hidden from view for about 250 years, enclosed within the walls of a later mansion built around it. Its rediscovery came in 1978 when that overlying structure was demolished.