Have you guys ever been to the National Museum of Scotland on Chamber Street in Edinburgh? If not next time you are in Edinburgh make sure you check it out! After being remodelled half was opened a while back but the second half (the best side I think) opened on 27th July 2011 and it is AMAZING!! One room is filled with life sized animals from Giraffes and Elephants to Chickens and Bats.. it really is fantastic! They even have a young children's section upstairs with some interactive bits (the fossil digging is a big hit) and the older section of the museum still has their room for older children and teens with a F1 car you can drive and loads of experiments and challenges.
The best bit?! It is totally FREE!! you could easily spend a whole week exploring it.. it really is a beautiful giant building. They also have a bistro, restaurant and a cafe on different floors and a library where you can ask questions or read up a bit more on your favourite subjects. They always seem to have some fun activities to keep children happy the first time I ever went they were making Christmas decorations, then they were holding a drawing competition and gave everyone clip boards with pencils and paper.. on the 31st of December they had a GIANT ceilidh on with a full band and instructions how to dance.. it was hilarious, there must have been at least 300 people dancing for 2 hours.
PS. If the weather is nice make sure you check out the roof terrace.. it has some people views of the city.