London cafe in spiral concrete shell has retractable windows

A spiral cafe with a rooftop garden in Chelsea, London, by architecture studio NEX has curved windows that can retract fully when the weather is good.
The windows of the the Cadogan Cafe can retreat into the ground, allowing the dining area to to spill out into the surrounding square.Wrapped in a slender arcade of 15-centimetre-thick concrete panels, the cafe is located on Duke of York Square, next to the Saatchi Gallery on King's Road.
The retractable, curved glazing elements use a chain system