European road trip in December

[LondonSuperTrooper]

We are taking our children on a European road trip in December. DS is 8 and DD is 7months.
Can anyone recommend child friendly activities in Bruges, Brussels, Amsterdam, The Hague & Rotterdam?

We went to Bruges a couple of weeks ago. Our 3 year old liked the Christmas markets (there's an ice rink and some mini fairground rides), koningen Astrid-park close to the centre with a great playground, and the Picasso museum, though that's not especially targeted at children.
His favourite thing was making his own hot chocolate and eating waffles. We went to The Old Chocolate House.

Amsterdam canal boat trip was fine albeit grey. Madame Tussaud's saved us when thunderstorms
Rotterdam viewing tower was very high, the cafe on the ground floor very child friendly, there is a pancake boat nearby at the harbour
Efteling might be magical this time of year

Nearly forgot..zaanse schans was a decent afternoon out...up a windmill, decent pics in clogs, hot chocolate, saw clog making workshop, had a waffle

This is great! Thanks for your replies.... I'm off to google it now