The ALPACA experiment is a new project aimed at wide field-of-view
high-sensitivity observations of high-energy cosmic rays and cosmic
gamma rays, launched between Bolivia and Japan in 2016. It is composed
of an 83,000 m$^2$ air shower array and a 5,400 m$^2$ underground muon
detector array, on a highland at the altitude of 4,740 m, halfway up
Mount Chacaltaya on the outskirts of La Paz, Bolivia.