At over 4,400 meters above sea level on the Qinghai-Xizang Plateau in Daocheng, southwest China's Sichuan Province, stands the world's most advanced cosmic-ray observatory – the Large High Altitude Air Shower Observatory (LHAASO). Since its completion in 2021, it remains the world's highest, largest and most sensitive observatory for detecting high-energy cosmic rays and gamma rays. CGTN's Liu Jiaxin takes us inside this mega-facility, where scientists are tracing particles from the universe's high-energy frontiers.