Skipton Castle is fully intact and privately owned, so full access is not allowed (yes, there is a family who lives there). But the half you can visit is the medieval bit, very well preserved. And the walk around the castle is highly recommended.
The ruins of Bolton Abbey, North Yorkshire, England.This, the largest of Yorkshire's four counties – and the largest county in England – is also the most beautiful. Unlike the rest of northern England, it has survived almost unscathed by the Industrial Revolution... Read more: http://www.lonelyplanet.com/england/yorkshire/north-yorkshire#ixzz3JhlLOAiC