Most of these mega mansions will be out of the reach of ordinary house hunters but they show what you could get if you have a few million pounds to spare.
From a 14th-century castle to a striking modern silo conversion, these properties are all truly unique and are priced from £4 million to £15 million.
Most boast extensive grounds, beautiful landscaped gardens and glorious views over the surrounding countryside.
As well as charming period features, they have plenty of modern touches, including cinema rooms, gyms, swimming pools and air conditioned wine stores.
Below are the nine most expensive mansions listed for sale on Rightmove, from the lowest to the highest priced.
For more amazing properties, take a look at these houses for sale on Britain’s most expensive streets.
7. Thornton Park Estate - £9,750,000
This vast estate between Thirsk and Northallerton, in North Yorkshire, spans around 633 acres and includes the site of the former mansion house. The estate also encompasses the Grade II-listed stable block, incorporating Park House. There are 12 residential letting properties and a mis of traditional parkland, landscaped gardens and lakes, with opportunities for development. | Rightmove/Savills Photo: Rightmove/Savills
8. Ripley Castle, Ripley - £15,000 (offers over)
This 14th century Grade I-listed castle in Ripley, near Harrogate, North Yorkshire, is looking for a new owner, having been home to the Ingilby family for more than 700 years. Highlights of this historic lakeside castle include the Old Tower, containing an oak floor which was originally part of the HMS Rose, an 18th century 20-gun frigate, and the Knight's Chamber, which is described as one of the 'most remarkable' Tudor rooms in the country. The Oval Drawing Room and the second larger Drawing Room, meanwhile, enjoy the best views over the lakes and deer park. | Rightmove/Carter Jonas Photo: Rightmove/Carter Jonas
9. Ling Lane, Leeds - £4,000,000
This huge seven-bedroom house, with eight bathrooms, is in one of the most sough-after areas of north Leeds and has an indoor swimming pool and leisure wing, a games room and a cinema room. | Rightmove/Tyron Ash International Real Estate Photo: Rightmove/Tyron Ash International Real Estate