Mamhead House, Exeter, Devon
A Grade I-listed, Georgian house set in parkland gardens with a Grade II-listed, 19th-century castle used as offices. The house has stained-glass windows and a library with carved wooden bookshelves. 16 beds, 10 baths, 9 receps, 11 attic rooms, 2-bed bungalow, 164 acres. £8m Strutt & Parker 01392-215631.