LE MANS, France -- Welcome to Le Mans, home of the oldest and most prestigious endurance motor race in the world.
Famously lasting for a full 24 hours -- whichever team has driven the furthest wins -- it's a brutal test of not only the driver's mental and physical prowess, but also the car's ability to maintain punishing speeds and manage tight corners with minimum time-wasting stops for fuel.
I went behind the scenes at the 2015 race here in western France to see exactly what happens. I peered inside the pits to watch the crews in action and watched high-performance race cars hurtle around -- and off -- the track.
An estimated 263,500 fans attended this year's race, from all over the world. A parade of flags representing all the teams' countries precedes the race, accompanied by national anthems.
Cars racing from four different power categories participate in the race, with LMP1 being the most powerful.
As the race begins, crews carefully push the cars down the pit lane and into position on the starting grid.
Crews make last-minute tweaks to the cars before they set off.
I had a spectacular view above Audi's pit lane to watch the crews at work as they changed tyres and refuelled the car with military precision. Not a second is wasted.
If you can't get a good view of the track, various massive screens -- branded with mobile racing game Real Racing 3 -- are dotted around to give you a look.
At times, the racers drive in a pack while maintaining astonishingly high speeds. It makes for exciting viewing, but with other cars so close, there's even less room for error.
The race takes place on the Circuit De La Sarthe, a 13.63km (8.47-mile) track that comprises both purpose-built race track and closed-off public roads.
All drivers have to master the turns of the track extremely well to know exactly how to take each turn. This Aston Martin driver slightly clipped the apex to corner this bend smoothly.
Although no cars in the Le Mans race are powered by electricity alone, most cars use hybrid systems that make clever use of what's known as energy recovery systems. Audi's cars, for example, use an inertia flywheel that harvests energy generated by braking and recycles it into the vehicle.
Porsche, meanwhile, uses batteries to store energy harvested from braking and from the heat generated by the turbo chargers.
The more energy that's recovered, the more efficient the electric part of the motor can be, meaning fewer stops for fuel and more time on the track, racing up laps.
Nissan has this year opted for a front-engined, front-wheel drive design for its Nismo LMP1 racing car. It's something of a controversial design for a Le Mans racer, and Nissan is the only team to go this route.
Only one of its four cars finished the race, and it didn't place in even the top 30.
The race was fought bitterly between Audi and Porsche. The Porsche began to edge ahead in the ninth hour, however, and went on to win having completed 395 laps of the circuit in the 24-hour period.
It is Porsche's 65th time racing at Le Mans.
The atmosphere in the crowd was electric. The cheering and clapping never subsided while the race prepared to start.
This chap played various tunes on his trumpet and decided to make use of a smoke bomb to create even more of a spectacle.
A note on my photography: I was shooting the race using a Canon 6D camera, mostly with a 70-200mm, f2.8 lens attached.
To get these sorts of blurred background action shots, it's important to use a slower shutter speed -- around 1/100 -- and pan the camera, matching the speed of the car as you take your shot. You'll hopefully then get a crisp shot of the car, but the slow shutter speed will have given a great amount of motion blur to the background and the track.
It takes a lot of practice, but over 24 hours, I had plenty of time to get it right.
Crashes do happen at Le Mans, and sometimes they can be catastrophic. This one was only a small tussle around a bend...
...and only resulted in this car spinning off the track. It entered the pit lane the following lap with some apparent damage, but nobody was hurt.
By roughly 9.30pm on the Saturday, the light is fading fast and the cars' headlights blink on. A beautiful sunset welcomed the racers into the night stages.
Down in Aston Martin's pit lane, a big stack of wheels are being prepared for the race. Wheels soon to be used are housed in heated tents, warming them up to make them better grip the track surface, reducing the time the driver needs to get them up to optimum temperature.
Rows of monitors display vital information about how Aston's drivers are doing and, critically, how the cars are performing.
The engineers' eyes rarely leave the screens for too long, so food is eaten at the stations.
The pit crew have to stay prepared for the cars to arrive at any time.
The truly dedicated fans turn up with their own hammocks and sleeping platforms. These guys barely left their position all night.
As night descended I began to get sleepy. Luckily, Audi's race centre, from where I'm taking many shots, has an endless supply of espresso.
For the fans attending the race, the ferris wheel has lit up.
With the lower light, it's possible to see the brake discs of this car glowing bright red as it brakes hard going into a corner. The carbon ceramic discs can withstand temperatures up to 1,000 degrees Celsius.
By using a slow shutter speed, I've captured the car brakelights as they snake through these bends.
It's now around 3am and this dedicated fan has positioned himself at one of the far corners of the track.
Good headlights are essential for much of the course, as there are no floodlights to show drivers where to go.
Audi may not have won the overall race, but its driver André Lotterer did produce the fastest lap time of 3 minutes 17.476 seconds.
Like all of Audi's road cars, the LMP1 racer is four-wheel drive.
Those brake discs are getting hot again.
I was almost falling asleep by this point. Thankfully, several drivers share the load to avoid them falling asleep at the wheel. In the LMP1 category, no driver is allowed to drive for more than 4 hours 30 minutes in total.
Nissan's car looks just as odd at night.
The pit lanes have various replacement parts for the cars, including this front end, ready to slot on if the existing one gets smashed. Crucially though, the driver is at no point allowed to leave the car during repairs.
Porsche's car is a beauty in black.
The sun rose and the pit crews continued to work hard, replacing tyres and cleaning windshields.
The LMP1 cars come down the straights at astonishing speeds, generating ear-splitting noise levels. After listening to the cars for many hours, a headache set in.