An intricate ceiling painting worth 18m euros (£15m) has been unveiled at the United Nations offices in Geneva.
The coloured dome took Spanish artist Miquel Barcelo more than a year to produce, using 100 tons of paint with pigments from all over the world.
He worked with architects and engineers to develop the extra-strength aluminium for the dome.
However, the Spanish opposition party has criticised the country's government for spending some public money on it.
The Spanish Foreign Ministry said the government and private donors helped pay for the artwork.
Of the public money, 500,000 euros (£421,425) came from a budget for overseas development aid and international organizations like the United Nations.
The Popular Party said that meant money which should have been spent on alleviating poverty was instead used to pay Barcelo.
The ministry insisted the funding for his work had been separate.
However, a news conference with Barcelo and Spain's foreign minister was cancelled in Geneva on Tuesday.
The artist recently revealed the inspiration behind his brightly coloured abstract.
"On a day of immense heat in the middle of the Sahel desert, I recall with vivacity the mirage of an image of the world dripping toward the sky," Barcelo said.
"Trees, dunes, donkeys, multicoloured beings flowing drop by drop."
As the work was unveiled, UN Secretary-General Ban Ki-moon thanked Barcelo for putting his "unique talents to work in service of the world".
He added: "The artwork you have created for this room is innovative and radiant.
"I have no doubt that people will come to see it whether they have business here or not."
The artwork can be found on the ceiling of the Human Rights and Alliance of Civilizations Room.