China has emerged as a science powerhouse in recent years, with the country's Communist leadership plowing billions of dollars into advanced research to contend with the United States and other rivals.

Its latest showpiece is the Jiangmen Underground Neutrino Observatory (Juno), a state-of-the-art facility for studying the minuscule subatomic particles.

The project is an "exciting" opportunity to delve into some of the universe's most fundamental—but elusive—building blocks, according to Patrick Huber, director of the Center for Neutrino Physics at the American university Virginia Tech, who is not involved in the facility's research.

AFP recently joined an international media tour of the observatory in Kaiping, Guangdong province, organized by the Chinese Academy of Sciences, the country's national science agency.

The lab is reached by a funicular train that travels down a tunnel to a cavern built 700 meters (2,300 feet) underground to limit radiation emissions.

Inside stands the neutrino detector, a stainless steel and acrylic sphere around 35 meters in diameter, crisscrossed by cables.

"No one has built such a detector before," Wang Yifang, Juno's project manager and director of the Institute of High Energy Physics, said as workers in hard hats applied the finishing touches to the gleaming orb.