The swans happily paddle around it and the herons are keeping a watchful eye, but the boaters are having more difficulty with the 7,506 oil drums that have been coloured and piled up to create The London Mastaba, Christo’s first major sculptural installation in the UK which appears almost surreal as it floats in the Serpentine and takes its name from the Egyptian tombs with sloping sides and flat roofs.

Across the road, (where you take your life in your hands with three different sets of lanes for horses, cyclists and vehicles, the cyclists being the least tolerant to pedestrians), the Serpentine Gallery has a fascinating exhibition on a forty-year interest by Christo and his late wife Jeanne-Claude in creating installations from oil drums, including a proposal for Abu Dhabi, as yet unexecuted, which would be many times larger than the Serpentine at 1.5 million barrels (on the outside – it is hollow inside).    The drawings and the website also show how The London Mastaba was constructed – no mean feat in the middle of a lake.

While some of the examples on display in the gallery show old rusty oil drums in their natural colours, those in the Serpentine have been more carefully picked, with different colours on the long facades shimmering like the feathers of ducks in the lake or the scales of fish, highly appropriate for its location.

Once the installation is removed, there will be a substantial investment in ecological improvements to the Lake; hopefully this will enable future installations next year and beyond, that will mirror the success of the Pavilion at the Serpentine Gallery, now in its 18th year.