There is a new information board here and they have cleared some of the wall at the back of the tomb away so that you can get a better picture. This is a truly impressive tomb and definitely worth a look. The capstone on top of it is massive and really would have taken some moving.
A few excerpts from the info board:
Labbacallee is aligned on the setting sun of the equinox, 22nd March and 24th September when the day is of equal length. On these days the sun illuminates the chamber.
The excavation in 1934, a womans Skelton was found. Her Skelton was found in the inner chamber, her head in the larger outer chamber.
Edit 15th April 2011
I sped down from work in Limerick to try and make the March 22 equinox at Labbacalle – my first problem was a sign-post on the Mitchelstown bypass that read Glanworth was only a few kms. Unfortunately it must be a least 14kms. I made it for about 6 30 but at this stage the sun was all but gone down as you can see from my pictures. If there is an alignment it must be from much earlier possibly 6 00pm.
Have a look at labbacallee.weebly.com