Drive 30 minutes south of Salt Lake City, past the modest homes and businesses that dot the city of Lehi, and you’ll come across a building in the shadow of Mount Timpanogos, whose unassuming façade doesn’t match the importance of what goes on inside. This is IM Flash Technologies (IMFT), and though you may not have heard of it, it’s a fair bet that if you’ve used a cell phone, a digital video player, a GPS, or even just a flash drive, you’ve been exposed to the work that’s done here.

The two companies formed IM Flash Technologies in 2006 to manufacture NAND flash memory for use in their products. Fifty-one percent of the output goes to Micron; 49 to Intel.

Since IMFT was established, it’s made some important public innovationssuch as dropping its manufacturing process from 50nm to 34nm (used in products such as Intel’s X25-M SSD) to the just-announced 25nm. But what’s generally remained secret to all but the 1,500 people who work at IMFT is exactly what goes on inside. For reasons as diverse as competition and contamination, no press has ever been allowed into the fabrication plant (or “fab”) itself, where the actual manufacturing happens.

Until now.

IMFT granted me, and about a dozen or so other journalists and analysts, a once-in-a-lifetime opportunity to tour the inside of the fully automated fab and see exactly where and how everything happens24 hours a day, seven days a week, 52 weeks a year.

As you may guess, this was hardly an informal process. Security at IMFT was incredibly tight, and no one was allowed to go anywhere without an escort. Exactly what we were allowed to write about was carefully scrutinized. Even entering the fab itself required donning a six-piece “bunny suit,” or light protect coverall garment that prevented skin, oils, or hair from polluting the cleanroom environment of the fab. It also involved leaving everything else outside, whether cell phones, cameras; laptop computers, and even pens, pencils, and paperanything that could potentially contaminate the area.

IMFT did, however, provide us with a collection of never-before-seen photos that depict life inside the fab, which we’re publishing here so you can get an idea of the meticulous processes that go into the creation of some of the most important technology used in your devices.

See the slideshow.