In a once-in-a-lifetime opportunity, I was granted access to the facility and even provided with my very own private tour thanks to Porsche’s Heritage and Museum department.

Since I did a full day’s driving in classic and contemporary Porsche Turbo models, my phone (and camera) was already starting to quit on me. Switching on all sorts of battery saving modes, I entered the enormous 9,905-square meter building and thought to myself: what I time to forget your power bank.

The first thing that greets you is a row of cars, draped in sheets with the Porsche crest emblazoned on it. As you pass by, you itch to catch a glimpse of what’s underneath, like seeing your bridge on wedding day. Even without lifting the veil, images form beneath your inner eye. The light, shining through the huge windows, draw familiar shapes. Then, at request, our guide lifts them. Only then do you understand the breadth of the collection.

This secret garage has been in operation for around 12 years now; before that, Porsche scattered them across various locations around Stuttgart. Today, a dedicated team keeps the entire collection working. Except for a few race cars stored at Porsche’s motorsports department in Weissach, all the carmaker’s series models, special versions, prototypes, and race cars since 1948 are stored here. Not only are they ready for display at the Porsche Museum with just a few hours’ notice, but they can also be taken anywhere in the world. Even more impressive is that 20 percent are registered and road-worthy—no mean feat considering many the cars here are racecars, so technically not road legal.

With Porsche celebrating 50 Years of Turbo, the focal point is the “Turbo No. 1.” Ferry Porsche’s birthday gift to his sister, Louise Piëch, it’s a one-off with a narrow body and a smaller turbocharged engine (2.7-liter versus 3.0-liter). Without any Turbo badging, the only indication of its potent nature is the sweeping rear wing. Silver on the outside, it’s upholstered with brick-red cowhide leather on the inside with the seat center panel in a red-blue ‘McLaughlin’ tartan pattern.

Surrounding it, as if in admiration of its predecessor, all generations of the 911 are present. Most of the serial production models have a number tag of “000” as to easily recognize them as pre-production models. Some do have proper VINs and this includes Ferry Porsche’s personal olive green 911 S with its missing front bumper overriders, aniline leather seats, and a fully working Blaupunkt radio. The same goes for the 911 Turbo (930) and 944 Turbo that I drove just hours earlier. As much as possible, Porsche doesn’t acquire any limited run model, but there are a few exceptions, including a 911 Dakar that was stolen and damaged in a police chase.

At the sides of the warehouse and at the back, cars are stacked up to the ceiling like toys in huge boxes. Here, you see various racing machines including those that have made Porsche the most successful manufacturer at the 24 Hours of Le Mans with 19 overall wins. Some, like the 919 Hybrid, are even kept in the same condition they won the most famous endurance race—bug splatter, duct tape, and all. Not a fan of Le Mans? A couple of Porsche race cars from its rally and Formula One days are there too.

It’s really all here—countless Porsche 356s from the early Gmünd models to the late Carrera 2, the Porsche 959, the Porsche Carrera GT, the Porsche 918 Spyder.

There are even oddities like a prototype that’s half a car on each side allowing for cost efficiency when it comes to design and engineering.

One in a while, a non-Porsche sticks out. A couple of Mercedes-Benz vehicles are tucked away here—a G-Class equipped with a Porsche 928 engine used as means of transport during the Paris-Dakar race. An M-Class used as a test mule to test out the running gear that will eventually become the Cayenne. A prototype of what will eventually become the 500E, but built on the C124 (coupe) platform.

And what’s that over there? Did Porsche also build a motorcycle? Yes, one. A Porsche engineer couldn’t stop himself from fitting the engine of a Porsche 356 into a bike. How about tractors? Sure. Porsche used to have them and they lasted up to the 1950s. Today, collectors haggle over these tractors that they flatteringly refer to as “Red Noses.” The warehouse has two of them, including the smaller Junior model.

Certainly, there’s enough here to outfit another museum. Without sitting areas, signs, or any of the digital fuss it’s hell for Wikipedia or a motoring journalist with his phone running on fumes. Take everything in though and it’s just rows upon rows of Porsche models. It’s heaven on earth for Porsche fans, who are not afraid of getting dusty fingers.

This Porsche secret garage will remain kept from public view, but hey, at least I’ve got these pics to share.