The building of the Oxford University Museum of Natural history amazing. This year they are restoring the roof which consists of 8500 diamond shaped glass panes and no pillar supporting the roof is actually the same as another; they all got different flower like decorations.
And that is just the building, not mentioning the exhibits like this Tyrannosaurus rex, many of which can actually be touched so a great place to go with kids.
But not 2013 because they restore the roof.