We were told that the Palace is closed off when the Queen in in residence - luckily for us she was not at home when we visited, as this proved to be a very interesting attraction. The entrance fee was included in a special Royal-Pass ticket that can be bought in Edinburgh (includes the bus tours etc) and proved to be really good value. The State Apartments are very interesting, and the Historic Chambers of Mary Queen of Scots were facinating. There are also the ruins of Holyrood Abbey to see as well. The audio guide is included and this makes it easy to meander through at ones leisure, whilst hearing all the historic input. I guess this would be ranked in the top ten of things to see in Edinburgh.