Bulgarian-born artist Christo has revealed his first major outdoor project in the UK - a sculpture composed of over 7000 oil barrels.
The Mastaba is a pyramidal sculpture of stacked barrels floating on the Serpentine Lake in London's Hyde Park.
The Mastaba is more than 20 metres high and cost STG3 million ($A5.3 million) to produce.
"All interpretations are open, because they all lead us to think - and thinking is what makes us human," Christo said about his piece.
He said the construction, maintenance and removal of artwork "will be entirely funded by me through the sale of my original works of art."
The Mastaba will float on the Serpentine Lake from June 18 to September 23.