A dark black pavillion with sloping roofs and rectangular lay out reminiscent of Ryonan-ji zen temple. Simple, yet perplexing, as you can never see the whole. Difficult to photograph too, with deep contrast between the shaded corners and the sunlight pouring in. The planting is ‘too big’, and densely packed so that there is a feeling of irrepressible swelling and nature filling the space.
Piet Oudolf’s herbaceous perennials and grasses have gone over now, with drying seedheads, as the pavillion ends its 2012 tenure at the Serpentine. Each year the gallery has a leading architect design the pavillion (last year here). This year Peter Zumthor referenced the medieval metaphor of garden as cloistered and pure like the Virgin’s womb. The garden is accessed by a narrow corridor that makes a double skin to the garden, with offset ways in to the garden itself, 
so that you have to penetrate as if through a maze from the outside.
On the busy day I was there, it was a far from sanctuary inside, but maybe the awkward movement and snooty chaos in the space added to the disequilibrium that may otherwise have been intended.
See more pictures in my flickr photostream