Raised up from the ground over a series of rugged quarry stones, the cylindrical pavilion is constructed from a paper-thin layer of white fibreglass, reminiscent of papier mache wrapped around a balloon.
Radić gave the structure a hollow centre, creating a central courtyard that is open to the sky. There are also various openings in the walls that form balconies, offering views out over the gardens.
"I've always thought that this is a really symbolic place," Radić told journalists at the press preview earlier today. "For me this pavilion is a folly, and the folly historically is a romantic place, a place of extravagance and a place of atmosphere. So this pavilion had to both occupy and create a symbolic place."
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Visitors can choose to either walk inside the pavilion, via a raised walkway leading up from the ground in front of the gallery, or they can stroll down underneath, where the large boulders both support the structure and offer places to sit.
"From the outside, visitors see a fragile shell in the shape of a hoop suspended on large quarry stones. Appearing as if they had always been part of the landscape, these stones are used as supports, giving the pavilion both a physical weight and an outer structure characterised by lightness and fragility," said Radić.
Grey wooden decking covers the floor, intended to create the feeling of a patio rather than an interior.
Radić designed the pavilion using a series of models put together from masking tape. His intention was for the structure to feature the same handmade qualities, on a grander scale.
"I feel like a giant made this model as a gift for London," he said.
Last year's pavilion was designed by Japanese architect Sou Fujimoto and comprised a cloud-like structure made from a lattice of steel poles. Other past commissions include Herzog & de Meuron, SANAA and Peter Zumthor.
Photography is by Amy Frearson, Dezeen, apart from where otherwise indicated.