The Oscillation Project with Emulsion-tRacking Apparatus (OPERA) is an experiment to test the phenomenon of neutrino oscillations. It exploits CERN Neutrinos to Gran Sasso (CNGS), a high-intensity and high-energy beam of muon neutrinos produced at the CERN Super Proton Synchrotron in Geneva, Switzerland, and pointing to the Laboratori Nazionali del Gran Sasso (LNGS) underground laboratory, 455 miles (730 kilometers) away at Gran Sasso in central Italy.