Serpentine Gallery's summer pavilion unveiled

The ninth Serpentine Gallery pavilion in London, which the architects Sejima and Nishizawa say 'works as a field of activity with no walls, allowing uninterrupted views across the park' Photograph: Graeme Robertson

Separate areas within the pavilion will contain a cafe and auditorium, where Park Nights performances, talks and film screenings will be held Photograph: Graeme Robertson

Describing the pavilion's reflective canopy, the architects say it 'undulates across the site, expanding the park and sky' Photograph: Dan Kitwood/Getty Images

They add: 'Its appearance changes according to the weather, allowing it to melt into the surroundings' Photograph: Dan Kitwood/Getty Images

Sejima (left) and Nishizawa pose beside the new pavilion, their first built structure in the UK Photograph: Dan Kitwood/Getty Images

The metal roof varies in height, in some places veering towards the sky and in others, sweeping down almost to the ground Photograph: Graeme Robertson

Sejima and Nishizawa inside the pavilion. The structure's reflective materials make it sit seamlessly in the natural environment, they explain Photograph: Graeme Robertson

The roof sits atop a series of delicate columns, reflecting the people below Photograph: Shaun Curry/AFP/Getty Images

Sejima and Nishizawa are interviewed ahead of the pavilion's unveiling Photograph: Graeme Robertson

... and given the paparazzi treatment Photograph: Graeme Robertson

Ultimately, say the architects, the pavilion is 'a sheltered extension of the park where people can read, relax and enjoy lovely summer days' Photograph: Graeme Robertson