Somewhere unusual to stay in the Midlands / East?

[bottersnike]

We've got our summer holiday planned and will be heading off to Norfolk. I'd like to start the holiday off with a night's stay somewhere unusual between where we are (Gloucestershire) and Norfolk.
Ideally, I'd love to find a windmill, treehouse, castle etc that the kids (aged 8 and 11) and us adults would all love!
Does anyone know of somewhere like that? I've tried the usual sites (goglamping etc) but not found anywhere so far.
Any recommendations would be really appreciated!
Thank you!

[PicaK]

Google windmill weatheroak - looks like you can rent it out on roomcheck. It's v near J3 of M42 and there's a lovely pub just down the hill. Amazing views!
B48 7EA. Might be too near home though.

When i win the lottery i am going to buy it!