The Serpentine Gallery Pavilion 2012 designed by Herzog & de Meuron and Ai Weiwei is described as an opportunity to inspire visitors to look beneath the surface of the park as well as back in time at the ghosts of the earlier structures.
With its cork surfaces and dark corners what it really is is the ultimate children's playground. It will be hard to visit it without finding screaming children running about, hiding from each other in the dark corners and leaping over the uneven surfaces. There is place for a good coffee, but this year's pavilion is a cork dungeon for the children. The little buggers will love it...
It is open until 14 October.
Be sure to also catch the other free exhibition at the gallery itself - Yoko Ono's To the Light which runs until 9 September.