Thorpe Perrow Arboretum and Falcons.
The Arboretum has one of the largest collection of trees in North Yorkshire, I did think my two boys would be bored looking at trees but we were very lucky to be there when a man was doing a demonstration of chainsaw sculptures.
The falconry display was also very good despite us having to sit through a 20 minute downpour. The falconry is not for the squeamish, but the children get a chance to handle the birds and the adults may even get landed on if they want.

On the website it says they can organise educational packages so if a few people want to go it might be worth giving them a call.
