Have you considered the Lake District as a destination?
If you're tempted I heartily recommend taking a trip to the Alnwick Garden. Apart from being a totally stunning, full-on grand scale, hands-on garden with endless things to do and see, they also have a jam packed calendar of events. In May alone, perfect for kids, is Grow your own dinner, Coffee and Crayons and Tales Unlimited (Fantasy storytelling with music, movement and aerial dance).

Truly worth a visit.

Take a look at our Lake District destination guide, with tons of other ideas.

Have fun!!