Lizzie,
This name is all too familiar to me, as one of your posters replied, it is now known as Oak park, very close to Carlows GAA grounds if I recall. it is an old mansion on very extensive grounds owned at one time by the Cokes/Cookes of Painstown and then sold to the De Bruin family in the late 1700's.
I am a descendent of the Painstown Cookes. Oak park estate is owned now by the Irish government's department of agriculture, and on the grounds there is a church and graveyard, though rather old and run down. I will post the coordinates here for you, and you can copy and paste them to google maps, and you will see where Painstown once was. Hope I have been of help

52.865822, -6.913502
Pete