Supernova neutrino detector. Tunnel A at the Gran Sasso Laboratories in Abruzzo, Italy. In 2003, this tunnel system is the largest underground laboratory for particle astrophysics in the world. The experiment housed in this tunnel is designed to detect supernovae (catastrophic star explosions) by detecting the neutrinos that they produce. Neutrinos are elementary particles which can travel through solid rock. The laboratories are located 1400 metres underground, and are accessed from a 10 kilometre long road tunnel. The rock overlay shields the laboratories from cosmic rays.