VERSAILLES, FRANCE • It is so big he claimed it "almost holds up the sky".

But Danish artist Olafur Eliasson refused on Monday to reveal just how tall the giant waterfall he has created at France's Palace of Versailles actually is.

"The height is perfect," he told reporters as he unveiled the spectacular installation, which cascades into the Grand Canal of the famous royal gardens outside Paris.

"Just as I intended, it will obscure the sun when it sets" on Midsummer's Day, said the artist, who has previously wowed New Yorkers with his 10-storey urban waterfalls and Londoners with a huge trippy sunset at the Tate Modern gallery.

"Of course, I could tell you how many metres it is, but I am not going to because we need to leave it to the public to make up their minds how high is high," he said.

Earlier, he admitted to Agence France-Presse that he was "behaving like a small arrogant king" in not revealing its height, adding cryptically that the "size of the waterfall is decided by the confidence in the more cosmic Baroque".

He said he wanted to get away from a "world where everything is reduced to statistics... to resist the idea that we have to always quantify the unquantifiable".

Instead, he insisted the eight works that he has created for the palace built by "Sun King" Louis XIV, the most absolute of France's absolute monarchs, were made to give "everyone the chance to become a king and queen".

"It is about decentralising the hierarchy of the perspective... to let everyone winkle out the secrets" of the visual tricks Louis XIV and his architects used to impress visitors to Versailles.

His other works include what he hopes will be an enchanted misty ring in one of the gardens' many groves called the Fog Assembly in which visitors are encouraged to "lose themselves".

Unfortunately, its full effect was somewhat obscured by a real fog on the morning of its opening. The waterfall too was sometimes lost in the mist.

An enormous fountain had featured in the original plans for the baroque 17th-century palace drawn up by Louis XIV's architect Andre Le Notre, but was never realised despite attempts to pump water over a hill from the river Seine. "We are going to make the impossible possible," Eliasson had earlier declared, "to make dreams come true."

But Mother Nature in the shape of the floods that swelled the Seine last week almost undid his plans, the 49-year-old artist admitted.

"Several people... kept working in the downpour while their homes were threatened by the water," he said, paying tribute to the workers who helped install the artworks.

Climate change is a major theme for the artist, who grew up in Iceland. Another of the works he has created in the Colonnade Grove at Versailles is from dust left by a melting Greenland glacier that also featured in an installation he made for the COP21 (Conference of Parties) climate change conference in Paris late last year.

"For some people, it might look like worthless mud," he said, but the fertility of "this dust is what made civilisation".

His installations - on show till Oct 30 - follow British-Indian artist Anish Kapoor's controversial "Queen's vagina" sculpture at the palace last year.

It was repeatedly defaced, once with anti-Semitic graffiti, which drew condemnation from French President Francois Hollande.

AGENCE FRANCE-PRESSE