Floating on The Serpentine lake in London's Hyde Park is an installation by Bulgarian artist Christo Vladimirov Javacheff, better known as Christo.
Inspired by the trapezium-shaped burial tombs of ancient Egypt, The Mastaba is made from more than 7,000 brightly coloured oil barrels stacked 20m high, said broadcaster Deutsche Welle.
The artwork, which was officially unveiled to the public yesterday, coincides with a retrospective on the environmental artist in the nearby Serpentine Galleries. It will remain on the lake until Sept 23.
Christo originally conceived the idea of The Mastaba in 1977 with his wife Jeanne-Claude, who died nine years ago.
That project was supposed to be built in Abu Dhabi using 410,000 barrels, but has not won approval yet, according to United Arab Emirates' National newspaper.
If it is built one day, it would be the largest sculpture in the world.