Ron Arad's Curtain Call at the Roundhouse

A circular enclosure, a curtain suspended from the circular structure of the Roundhouse, forms a 360 degree projection screen. The curtain is made out of silicone rods, like plastic tubing but solid, hung from a circular rail high up in the Victorian ironwork. Like a bead curtain, the rods form a vertical surface but the ends hang free, and you enter by parting the strands and pushing through. The circle is eight metres high and 18 metres across. Twelve projectors, precisely aligned, make for almost seamless all-round projection. Outside the circle, a ring of twelve monitors surrounds the control desk.

So much for the technology. This works as an immersive experience: walk in through the moving image, sit inside surrounded by movement, walk around the outside trailing a hand against the rods, watch the interaction of people and installation. There is a rolling programme of twelve specially created works. The best use the whole space, like Matt Collishaw's Sordid Earth, a tropical thunderstorm mixed in with time-lapse footage of withering orchids. Others simply repeat a projection round the circle, with different degrees of success. Javier Mariscal does that but creates plenty of excitement with his animations and, like Andy Warhol, makes a virtue of repetition.

The Roundhouse advises 'pay what you can' which effectively means pay the recommended five quid, or risk embarrassment on a level with asking for tap water in a restaurant. Some cushions would have been nice - I bet Ron doesn't care to sit on a hard lino floor for two hours.

Serpentine pavilion 2011

Every year the Serpentine Gallery creates a new pavilion for the summer, a temporary architectural masterpiece (usually) designed by a famous architect who has not as yet built anything in the United Kingdom. This year is the eleventh in the series, the first in 2000 being Zaha Hadid (designer of the ill-fated Aquatic Centre for the London Olympics). This year we  have Swiss architect Peter Zumthor, famous among architects but otherwise little-known, who has designed a huge black box. This doesn't seem like a promising start on paper, but walking across Kensington Gardens, interesting qualities become apparent. The simplicity of the shape is unpretentions and sits in contrast to the relatively ornate Serpentine Gallery and the lush midsummer trees, in an oasis of startlingly bright green new grass. Each long black wall has three black open doorways, giving nothing away. The scene is enlivened by a severely plain string of white lights, although garish red 'keep off the grass' notices rather spoil the green-and-black colour scheme.

The building is black inside and out, a plywood structure covered with some kind of black tarry-looking fabric - even the floor. Through each doorway, you enter a black corridor so dark the lights are on all day, leading indirectly to the interior. The inside is the main point of the pavilion, an enclosed garden with an overhanging roof and blue bench seats all round, and sumptuous planting in the central part, open to the sky. It does make you want to sit and contemplate, which is Zumthor's expressed aim here. Notice the fire extinguishers: the architect clearly anticipated the need for those, unlike the signs outside, and was able to avoid any hint of colour: they are chromium plated shiny silver. The planting is by Piet Oudolf, the Dutch landscape designer who pioneered the use of ornamental grasses in his gardens, and is recently known for the High Line landscaped walk in New York. Red flowers mainly, and the trademark grasses, just high enough to slightly obscure long views. Catch it before it closes on 16 October.

Tottenham reflects

Residents at a street meeting on Monday evening at Tottenham High Cross. Like speakers corner but with much more urgent things to talk about.