Perfect - at that moment

I prefer to stay away from London in August, because of the crowds at exhibitions, and so it was on the very last day of July that we went up to see this year's Serpentine Pavilion. Last year's was distinctly RED, but this one is well and truly black. Designed by Peter Zumthor, this pavilion is enigmatic on first view.

It was a warm sunny day, the first that really felt like summer, and at first glance the pavilion did not look inviting. I loved the surface, however: a fine scrim all over, and with the entrancing shadows of trees fluttering in a pleasant breeze.

Very early on a Sunday morning, London reminds me of how it was when I first started work here nearly 40 years ago. At lunchtime I sometimes came over to Hyde Park for a stroll: an oasis that feels miles away from all the frenetic bustle. And on entering the pavilion I was filled with delight.

An intriguing dark corridor all round the structure leads to its interior: that place of cool and calm that I craved. One of my favourite aspects of hot bright days is the effect enjoyed in a cool dark room with just enough slats in shutters to let in slivers of that heat outdoors, or a well shaded verandah just like the open atrium design of this space.

Inside this calm sliver of shade and light is planted a bed of cooling plants designed by Piet Oudolf. No matter that many are bright red, the effect is of cool. The open area above them is large enough to invite breeze and bees, and with only two other visitors besides us two, it was bliss.

As ever with the Serpentine Pavilion the cafe tables and chairs are designed to fit. There is a dark blue wooden bench all around the four walls, and tables and stools which look a treat when unoccupied. We were fortunate to see it like this.

As it filled up the space quickly felt more crowded and noisy. The calm disappeared as snaps were taken of folks standing in front of the plants, and groups each in their own bubble intrude into the peace of others. We left before this happened to us.

In this way, I would say that the design is a delight if experienced with few others, unlike the design by Frank Gehry a couple of years ago which embraced occupants, making of us all a theatre for each other. But for me, this year's Pavilion was perfect while we were there.