Occupied continuously since the 1740s, the early cellar vaults of 'Fairy Hill' survice but its private beach became a swamp after the first railway in Ireland was opened in 1834. Permission was granted to Richard S. Guinness in 1842 to fill in that swamp and create a walled garden. Then standing on a 1.2ha site overlooking Dublin Bay with Howth Head on the skyline a new house was built in 1857. It was re-named, reflecting the importance of the spring well which provided water for local homes and for watering horses. The present owners acquired the house in 1942.

The garden was re- designed by Mitchell & Associates and now contains a formal or Italianate garden with classical temple and adjacent to the house, a herb garden. Helen Dillon advised on the planting. It was awarded first prize in 1996 by The Irish Landscape Institute.

Deepwell contains a collection of Irish paintings and furniture.

Open:
3rd January - 1st February
1st June - 30th June
18th August - 28th August

Admission:
House and Garden: Adult €7.00
House Only: Adult €5.00