Most homes these days are full of right-angles; square or rectangular rooms are easier to build and certainly easier to furnish.
But some of the earliest houses were round - and there's no doubt that a circular space can feel particularly cosy and welcoming.
These days, it's only rarely that a room this shape is included in a new building. But thanks to a trend for unusual conversions, there are a surprising number out there.
We've rounded up six houses on the market right now that each boast a circular room.
This quirky home was built in the 1880s by Dr William Price, a famous Welsh eccentric and physician. It was supposed to form the gateway to a museum of Welsh life - but the museum was never built.
The round part of the house is made up by a living room on the ground floor, with two circular bedrooms stacked above. There's also another, boringly-rectangular bedroom, a dining room and good-sized kitchen, and outside there's a garage and garden with pretty views. The house costs £214,950 through agent Dylan Davies.
Originally a Martello Tower dating back to 1810, The Q Tower is now a unique three-bedroom home. The design could make you dizzy, with a three-bedroom annexe spiralling round a semi-circular kitchen/breakfast/family room.
Upstairs, two of the three bedrooms in the main house are on the small side considering their pie-slice shape, but the whole place is brimming with history and character. And naturally, given its former function as a defence post in the Napoleonic War, there are amazing sea views from the roof. It costs £750,000 through agent Strutt & Parker.
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This classic oast house is a 'twin bottle' design with two circular hop-drying kilns. On the ground floor, one forms the entrance hall, with stairs up to a round landing, with the other becoming a kitchen that can't have been easy or cheap to install. Upstairs, the master bedroom has a semicircular ensuite bathroom and dressing room.
The rest of the house is just as charming, with a lovely drawing room and dining room, and three further bedrooms and family bath. Outside, the gardens include a large natural pond fed by a waterfall. It's available through agent Weald Property, for £725,000.
The only place you'll find a corner in this former windmill is in the one-bed guest annexe - all of the principal accommodation is round. On the ground floor, it's sliced up into pie-shaped wedges, consisting of hall, dining room, bathroom and kitchen. Above are two bedrooms and a landing, with two huge, fully-circular, living rooms on top. It's a long trek down, though, to the only loo.
As you'd expect, there are fantastic views from the top, and there are large gardens and a double garage outside. It costs a round half million through agent Connells.
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Crowborough, East Sussex
Coes Hall is a charming Tudor hotchpotch of half-timbering, brick, tile and thatch set in nearly 50 acres of parkland. The seven reception rooms include a circular timber-and-glass garden room with a thatched roof and lovely views over the garden and lake.
While some of the decor might not be to everybody's taste, the 11-bedroom house has every luxury, from an indoor swimming pool and gym to a cinema room. And the gardens are simply stunning, with a wisteria walk, water garden and even a folly. Of course, all this doesn't come cheap: available through agent Sotheby's International Realty, the house costs £4.5 million.
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But you don't need to spend seven figures to have your very own round house - as long as you don't mind somewhere cosy, that is. Puglia, in Italy, is famous for its trulli - tiny dry-stone buildings with conical roofs.
Trullo Tre Coni, as its name implies, consists of one main circular room with two round alcoves off to the side. At just 40 square metres, it's pretty snug, but the 12,000 square metres of land mean it might be possible to extend. Right now, it's home only to a pile of farming tools - but it could be yours for just €40,000 (£34,713). Contact Elite Puglia for more details.