I really recommend a visit if your are in the area. The guided tour last about an hour and costs £7 each, but you can go in the public side for £3 per person. Next door is Waterlowe Park - a gorgeous place to sit in the sun whilst the children play, and there is a rather nice cafe which is not too outrageously priced.
Hope you are all enjoying the sunshine. I'm having quite a relaxed first day of the Easter holidays (apart from getting Emily to do her GCSE coursework, but that was never going to be easy!!). Hope you are having a good one too.