One of the coolest castles we saw in England this spring was Brougham (pronounced "broom") Castle in Cumbria. Not only does it have well-preserved ruins and stairs leading all the way to the third floor, but I love the story behind this castle.
Unlike other females at the time, Lady Anne Clifford was supposed to inherit her father's properties, including Brougham Castle, upon his death. However, they went to an uncle instead. So Lady Anne spent years getting back the Clifford properties and restoring them. She actually died in Brougham Castle in 1676, in the same room her father was born in.
This castle is going to be featured in a couple of scenes in Book #3 of my WWI trilogy - and may involve an aeroplane ride and a kiss or two. ;)