I grew up in Wales and this was my favourite destination for a day out as a child.
To me it truly was a fairytale castle and I never tired of visiting the amazing gothic fantasy interiors.
Revisiting as an adult I realise now that there is so much more to the castle than just those wonderfully decorated rooms (not that I don't still love them as much as ever!)
There really is something here for everyone. Roman walls, a medieval keep, a world war II air raid shelter, the battlement walk, a welsh miilitary museum, a falconry. It's a full day out, so even though the entrance fee seems a bit pricey at 9 pounds, you get a lot for your money. And the prices in the cafe and gift shop are very reasonable.
My favourite part is still the amazingly decorated rooms though. These days some are open to the public as part of the general admission and you just walk through on your own. When I was a kid it was all guided tours with guides that knew all about every aspect of the room decor. It's a shame that the information sheets just can't do justice to the amount of information that could be given out about these rooms.
The rooms accessible with the basic admission price seem to encompass the banqueting hall and library, and a few other rooms including what seems to be everyone's favourite: the Arab room (which is the ultimate in sumptuous decoration). However, unless they change this set of rooms on different days, I guess you can't get to see my personal favourite rooms unless you pay for the extra guided tour. But believe me if you like this sort of thing you like it's worth paying for that extra guided tour to see those extra rooms - including the nursery and the roof garden. The nursery is where my childhood hero, the invisible prince, hangs out (you'll have to do the tour to see what I mean).
Incidentally, if you are into this gothic fantasy stuff and you really want to see a fairytale castle go north from Cardiff and check out Castell Coch. This was the Marquess of Bute's hunting lodge and is also decorated by Burgess. But it's setting on a hill in the woods, and it's external profile with lots of turrets, is more fairytale like than Cardiff castle. Castell Coch is much smaller though. read more