About the wax museum...it is quite pricey and I found that if I didn't know much Spanish history, I didn't understand the displays. I wish I had a Spanish guide to take me through and explain everything. The horror chamber is pretty macabre, too, which was great for a 16 year old, but might frighten an 11 year old.

We took our 8 year old to the Was museum this year too. It was just ok. If you have never been to a wax museum, then it might be fun. The horror chamber was too scary for her.
I don't think it is an essential place to go when you only have a limited time in Madrid, but since we go every summer it was a way to pass the day.

well it depends ,my boys are coming to Madrid and Spain since they were 1 year old and been all over with me in several ocassions.
The wax museum was nice even at 8 ::) But of course, they speak Spanish too lol!