Claiming to be the world's largest building by floor space, the 1 760 000 square metres of the New Century Global Center are a monument to growing Chinese consumer power, packed with shoppers - and beach bathers a thousand kilometres from the coast.
Home to hundreds of shops, restaurants, offices, a cinema and ice rink, the cavernous building in Chengdu, deep in southwestern China, also hosts a water park featuring a pool modelled on the seaside.
"The indoor ocean attracts me more with lots of facilities and activities like surfing and water skiing," said Gao Nini, 31, who paradoxically travelled from the coastal city of Qingdao to visit.
"We have the sea but I'm worried I would get tanned," she said of visiting the beach in her home town.
Ringed by a concrete beach, hundreds of bathers - wearing obligatory life vests - splashed in the waters' artificial waves, which are generated at intervals.
Behind them stood a bell tower resembling St Mark's Basilica in Venice, and a monumental screen relaying South Korean pop videos.
The Global Center project has seemingly defied critics who condemned it when it opened in 2013 as an example of China's wasteful construction boom, which has left swathes of empty houses outside many cities.
Along with a railway line to Europe and a convention centre that recently hosted a G20 finance ministers' conference, the massive structure is part of Chengdu's bid for top-tier city status.
Exact figures are not known, but the local government is reported to have spent more than $6 billion on it.
The Chengdu Commercial Daily reported that 90 percent of commercial space in the complex has been rented, while a staff member told AFP that some 8,000 office workers commute there each day.
Even so it has not escaped political controversy, with reports linking its construction to Zhou Bin, the jailed son of China's former security chief Zhou Yongkang, who was himself jailed for bribery last year.
The millionaire behind the building, Deng Hong, went missing during a probe into Zhou but was later released, local media said.
Inside the centre, the pool is ringed by restaurants where customers in swimming costumes ate pizza and hot orange juice - but the hard-surface beach left some pining for a genuine seaside experience.
"I have never seen the real sea but I want to see one and go surfing," said seven-year-old Liu Qingsong. "The (fake) sea looks good but it's not as good as the real one."