I went there two years ago and he wouldn't let me up to see it. His weak excuse was that there were crops in the field (this won't wash at this time of the year). I told him that I had a good knowledge of the countryside and I would take every care not to do any damage – he wasn't having any of it. I couldn't find any alternative route so I gave up. You may be able to get there by going along the banks of the river, though I doubt it. FourWinds?

Alternatively, give it a go. As I recall, he doesn't grow crops - he's a sheep farmer. I think Ken gave it a go, but got nowhere.

I was allowed up by his son while he was out. He came back as I was leaving and scowled a bit. I spoke to him briefly and he seemed like a really nice man in a hurry to get rid of me.

Same story here, incredibly he tried to tell me it was gone, then it was never there, eventually 'there's no visitors anyway'... That was way back in 2004 or 2005.

Technically there is supposed to be a right of way along the banks of rivers (one passes near the tomb) but you would still be trespassing at the site itself.

Think I've solved the mystery. Its the radon gas;

http://glasnost.itcarlow.ie/~feeleyjm/dolmens/carlow-dolmens.pdf

Also looks like you'll have no problem getting in if you go up there twirling a couple of rods ;)

This bloke seems to have gotten in fairly recently;

http://www.megalithicmonumentsofireland.com/COUNTIES/CARLOW/Ballynoe_PortalTomb.html

He's been fairly busy. Links to your site as well.