Here's Ballybrack.
http://www.megalithomania.com/show_site.php?site_id=8
I actually only gave this site 1 star, but everytime I drive past it or think about it the more impressed I am with its grim determination to hang on in there. I mean, it lasted ok for 4500 yers and the the 1970s+ happens to it. As you can see it's very open and I believe the red paint was from a time when it
was more protected. It stands the Cromlech Housing Estate (seriously ... what an address!)
,essentially one of the 'poorer' housing estates of
Dublin.
or consider Browne's Hill Dolmen. Very open and yet unabused, in fact quite a few local kids hang out here
and seem to respect it, but then this place appears in
all their school history books!