We booked to stay at Astley Castle a couple of years ago.    One has to hover near a computer when booking opens and I forgot, so the only time available was a December weekend, when everything is water logged.   It’s an amazingly sensitive intervention by Witherford, Watson Mann into the fabric of the small medieval castle, not pretending in any way to be historic, but using robust materials, brick and wood, and adapting the building and the bedrooms to the available spaces:-