I visited Apple's secret testing labs - here's what REALLY happens behind-the-scenes at the Cork campus

Apple is best known for its futuristic, spaceship-like headquarters in Cupertino, California. But what many people don't know is that the tech giant also has a huge campus in Ireland. Apple's Cork campus opened its doors in 1980 with a single manufacturing facility and just 60 employees. Fast-forward to today, the site is home to more than 6,000 employees, and serves as Apple's European headquarters. The tech giant is usually extremely private about what happens behind closed doors.