COPENHAGEN (NYTIMES) - It was designed by Bjarke Ingels, the renowned Danish architect, and cost US$24 million (S$33 million) to build. It was inaugurated by Queen Margrethe II, Denmark's reigning monarch. And it now accommodates a celebrity couple with peculiar eating habits and an almost year-round animosity toward each other.

Welcome to Copenhagen Zoo's new panda house.

Officials at the zoo estimate that the combination of adorable animal starpower and innovative Danish design will draw an additional 400,000 visitors per year.

"For such an iconic animal, we needed an iconic setting," said Bengt Holst, the zoo's director. "You wouldn't put the Mona Lisa in an ugly frame."

But not everyone is a fan of the new house, a circular enclosure in the shape of the yin and yang symbol that has made front-page news in Denmark over the past weeks.

Opponents believe the pandas, which are on loan from China under a 15-year agreement requiring the host to pay US$1 million annually, will limit Denmark's willingness to criticise Chinese policy. The campaign to bring the pandas to Copenhagen began in 2010, just after Denmark's parliament approved a memorandum recognising China's sovereignty over Tibet. Although the panda house is privately funded, some also object to the project's cost.

Shaped like the Chinese symbol representing opposites in balance, the enclosure has two tilting halves. Visitors can observe the pandas from above, or from a ground-level restaurant where they can dine while watching the male panda, who spends most of his waking hours scarfing down bamboo, at close range.

"Normally, zoos have a front of house for the audience, and a back of house for the animals," Ingels said. "We thought we would make this 360 degrees, so that no aspect of the pandas' life was off limits."

The panda's unusual mating habits posed the main challenge for the architects. Male and female bears only mate during two or three days each year; the rest of the time, they must be kept far enough apart that they cannot see or hear one another.

"We didn't want to have two separate structures," Ingels said. "And we wanted to stay away from the typical pagoda. We realised that this ancient Chinese symbol, of black and white, male and female, offered the architectural solution."

A separate area within the enclosure - normally a sort of no panda's land - will be opened to both bears during their exceedingly brief mating season and includes trees that the female panda can climb up if her suitor is not to her liking. The rest of the year, the animals will live mostly outdoors in their separate areas, which have been landscaped to resemble the panda's two main habitats, a dry bamboo forest and a denser woodland kept misty by a fog machine.

The pandas have already proven popular - 5,000 people showed up for Thursday's public opening, double the average attendance on that day - but so has the structure.

Karsten Ifversen, the architecture editor for the Danish newspaper Politiken, said that while pandas were "very lazy animals", the enclosure "goes in the opposite direction". "There's a lot going on everywhere you look," he said. "The architecture is almost as much an attraction as the animals."

As for the cost, the pandas do not have the most expensive home in the Copenhagen zoo. The elephant enclosure, for instance, was designed by Norman Foster and cost more than US$36 million.

But for critics, the panda house is not so much a feat of animal architecture with a hefty price tag than it is a signal of overly cozy ties with China.

Pointing to other instances of so-called "panda diplomacy", both the far-left Unity party and the far-right Danish People's Party criticised the new enclosure as a symbol of political appeasement.

"Denmark gets the pandas because we have dropped our criticism of the Chinese repression of Tibet, and because Chinese human rights violations aren't being criticised so much," Eva Flyvholm, a member of parliament for the Unity party, told the Danish television station DR.

The Danish government has welcomed this new phase in its relations with China. When the panda loan was confirmed in 2014, it was accompanied by 40 new trade agreements between the two countries.

At the panda house's inauguration on Wednesday (April 10), Mette Bock, Denmark's culture minister, said in a speech that this was a project "about friendship". But outside the zoo, a few dozen protesters dressed in panda suits disagreed. Cecillie Sita, 19, and Christina Kalesh, 18, said they were protesting because they objected to Denmark "kneeling" before a country that violated human rights. They said they were disappointed by Ingels' decision to design the enclosure.

"As a representative of Denmark, it would be nice if he came out in favour of human rights," Sita said.

Ingels said the protesters - and the media - were overblowing it.

"The fact is, we all collaborate with China - just look at the phone in your pocket," he said, adding that the previous night he had seen firsthand how excited people were by an invitation to dine at eye-level with the pandas.

"At the end of the day, this is about two really cute animals," he said.