This is old news.
For those who missed it, here's a report on the 24hr museum:
"29.04.2008 - Top Welsh Megalithic monument open again for visitors
A top Anglesey destination for megalith fans is open again to visitors.
The Neolithic burial chamber Barclodiad y Gawres in Anglesey has been closed for a number of months to remove graffiti, but the outstanding monument which overlooks the Irish Sea can now be visited again by appointment every Saturday, Sunday and Bank Holiday Monday between 12 and 4pm until 30 September.
As the chamber is reached through a locked gate, visitors wishing to see the monument should call into the nearby Wayside Stores in Llanfaelog, one mile north of the chamber, where they will then be accompanied to the chamber by a member of staff. Wayside Stores are contracted by Cadw to manage the chamber. "
