Access to the visitor centre near Newgrange is a short walk from a large car-park. The visitor centre is the only place to purchase tickets for excursions to Newgrange or Newgrange and Knowth. There is a special room inside the visitor centre with a full size mock-up of one half of the entrance passage so anyone in a wheelchair, with poor mobility or claustrophobia can have some idea of what it's like.
There is no wheelchair access for disabled people to the monument itself.
Newgrange is accessed by a walk downhill from the visitor centre to the minibus stop. There's a short minibus ride, then a walk uphill to the monument. Then there are several steps to negotiate shown clearly here
http://www.megalithic.co.uk/modules.php?op=modload&name=a312&file=index&do=showpic&pid=23914
and the passage is narrow in places.
Something is not right. This message is just to keep things from messing up down the road