1. Newgrange, Co. Meath, Ireland.

http://www.themodernantiquarian.com/site/898/newgrange.html

2. Haroldstown, portal tomb, Co. Carlow, Ireland.

http://www.themodernantiquarian.com/site/890/haroldstown.html

3. The Rock of Dunamase, Co. Laois, Ireland.

http://www.themodernantiquarian.com/site/7770/rock_of_dunamaise.html