I would visit Birr Castle, it is 130 km from Dublin.
http://www.birrcastle.com/locationOfBirr.asp
The world's largest telescope at the time, a 72", saw first light there in 1845.
http://www.birrcastle.com/telescopeHistory.asp
Things to see in 2007:
The galaxies M51 and M81/82 are high in the sky in March/April.
The attached files show the view overhead and to the north from Dublin on 20/3/07 at 10pm.
The maps are from SkyMapPro.
New moons are 19/3/07 and 17/4/07, that's the best time to see galaxies.