The tour begins here. These heavy steel doors lead onto the factory floor. Safety gear is a must, and I had to wear ear defenders at all times.

"This person is responsible for your safety." This won't end well for any of us.

The car's bodywork begins here in the "press shop", as these massive, several-tonne rolls of metal.

A crane picks the rolls up and transports them to the giant presses that stamp the shapes into the metal.

The workers are, I'm sure, quite glad they don't have to roll these things around by hand.

These individual sheets of metal are stamped to form smaller body panels or internal parts.

The panels are picked up by robots using suction cups and moved into position.

This is just one of the giant machines that press the body panels into shape.

The machines are capable of pressing with up to 5,000 tonnes (over 1 million pounds) of force. I suggested using it to compress coal into diamonds, but apparently that's frowned upon -- they love their coal here in the North East.

The smaller parts that come off the press are checked over by hand.

A close eye for detail is crucial.

Any imperfections are marked before being sent back.

It's difficult to get a sense of just how big this factory is.

The plant is split into three main areas -- body assembly, paint and final assembly -- each of which contain various different stages of production.

There are 6,752 people currently employed by Nissan in the Sunderland plant. Here are just some discussing, I presume, 21st century car manufacturing.

In here is where the giant press squashes the metal panels into shape. Don't reach in suddenly, it won't end well for you.

This several-tonne lump of metal is actually a new press head being moved into position to create different shaped panels.

This is one of the suction cups that allows the robots to clamp on to a sheet of metal.

These vast warehouses store row upon row of car parts. It's like going into an enormous shop, except the only things you can buy are car parts and they're not actually for sale.

This trolley drives itself around, following the black marking tape on floor. It picks up finished panels and deposits them in the storage rooms before returning for more.

Sometimes the sunlight pours in from open shutters on the roof and makes the working day that bit more beautiful.

These panels aren't heavy at this stage and are popped into place by humans before the robots start doing their stuff.

An army of robot arms spot-weld the panels together. It's hypnotic to watch.

The robots are able to perform the welds more accurately and faster than human hands.

Although there's quite a lot of sparks flying around, the machines are designed to create as few sparks as possible -- sparks mean wasted energy, my Nissan guide explained.

The car shells are then transported to the next stage on these tracks above the factory floor.

You can just walk around the tracks as the cars pass. You really have to keep your eye on where you're going though -- if I was to fall and hold it up, the entire production process would be delayed.

The skeletons -- in particular, the welding points -- are all thoroughly checked over...

...by hitting them with a hammer. Apparently it's the best way to check if everything has been properly stuck together.

If you wander far enough around the vast complex, you can find some beautiful sights.

Although it's very easy to get lost if you don't have a guide.

"Robot training cell" isn't just a great name for a rock band, it's where the robots are programmed with new manoeuvres for crafting new car models.

113 cars are made every hour by the Sunderland teams.

The plant is operational 24 hours a day, with different teams working different shifts throughout the week.

Here's another autonomous cart taking doors to be attached.

The plant operates using a "just in time" production method, meaning that components are only made and brought over as and when they're needed. This method requires all parts of the factory to work in strict cooperation, but means that huge stocks of spare parts aren't required.

More bits and pieces are securely bolted to the cars before they leave the body shop.

For those of you not up on your British geography, Sunderland is a city of 175,000 people in the North East of England, near the larger city of Newcastle. It has a proud manufacturing tradition -- people from Sunderland are known as "Mackems", reputedly from the local pronunciation of "make 'em". It should be noted that it's not usually this sunny.

This is the stage where the doors are attached. It's an important stage, unless you really like fresh air.

Make sure it's on good and tight, please.

These robots are responsible for crimping metal edges. It's incredibly precise work, but these arms are capable of performing it at speed.

The plant employs teams of people whose job it is to monitor the efficiency of the workers. It's not to pick out anyone who's not pulling their weight, but to see if there are easier ways of doing things -- does a worker need to walk that 6 feet to his tool chest, or could that be alongside him? Why have the worker bend over to pick something up when it could be placed at waist height?

On the bonnet goes...

...and a check over for any imperfections.

The cars are on a continuous track that keeps on moving as they're assembled throughout the plant.

Another autonomous cart. This one is able to move alongside the workers as they follow the cars, ensuring they always have the tools they need.

Thankfully this sickly green is not their final colour -- it's just a coating that will help the final paint stick properly.

This sealer is applied by hand. It takes a lot of practice to be able to apply it accurately and consistently in the tight time-frames the workers have to stick to.

The sealer is then spread out across the joins in the panels.

Robot arms then apply paint to the difficult to reach sections beneath the car.

As a natural button-pusher, I was consistently having to fight urges to touch things the whole way around my tour.

Still on their tracks, the cars are then brought through this tube, which looks suspiciously like a research lab that would house a crashed UFO.

Sadly, I found no aliens, but I was able to see the teams highlight any areas where the primer paint hadn't taken properly.

It's sanded away by hand and then marked with a sticker to be reapplied before the final coat is put on.

The cars are then taken through these dusters. They're similar to the big rollers in a car wash, but they're made from ostrich feathers and are designed to dust off any detritus that may cause imperfections in the paintwork.

The paint is then applied by hand using giant spray guns. The workers wear boiler suits hooked up to respirators so their lungs don't fill with paint.

I was able to hold my breath, sneak inside and grab some pictures -- with mild concern for getting my expensive camera clogged up with paint particles. It seemed fine.

This mass of light tubes is to help the inspection teams check for even the tiniest errors in the paint application.

This guy then uses his smaller paint gun to paint awkward places like inside the wheel arches.

Heat lamps are then applied to help dry the paint before the cars move on.

It's at this stage where I nearly brushed against a still-wet car, almost completely ruining the paintwork and meaning it would have had to go through the whole process again. I wouldn't have been too popular.

More robot arms pick the car up from the paint shop and move it on to the trim and chassis shop -- that's where all the internal bits of the car are put into place.

This is one of the batteries that slots inside the all-electric Nissan Leaf. The batteries are made on-site  as well, but it's a closely guarded secret and Nissan wouldn't let me see. Boo.

*BEEP BEEP* If you don't get out of the way, things can get really bad, really fast.

This assembly line is where the doors are fitted with the windows as well as the electronics and motors to make them move up and down.

All the crucial electronics are threaded throughout the cars.

The centre console -- including the wheel, dashboard and all the knobs and buttons to operate the heating and stereo -- is delivered as one piece.

It can simply be inserted into the car.

As with the rest of the components, the centre console is delivered just in time for each car by automated trolleys.

The windshield is put into place and sealed around the edges.

Nissan makes everything on site, including the engines. There's a casting factory where the cylinder heads are made, but I sadly wasn't allowed inside.

This endless line of tiny components would be extremely confusing to understand, but green lights appear above each box as the worker pushed the trolley down the alley so they know exactly which pieces to take.

Good to know.

Items like the fuel tank, oil tank and other crucial bits and bobs are put into place.

The electric batteries are inserted into the Leafs (Leaves?).

They're heavy, so a helpful robotic platform does the lifting.

All the other parts, like indicators, head lights, bumpers and brake lights are attached and connected.

The wheels are delivered on this cool lift.

They're popped into place, then a chap with what looks like a terrifying laser weapon secures them in place.

Don't forget the front ones.

The strength of these machines means it's much less likely your wheels are going to suddenly fall off while you're driving along.

The cars are pretty much finished by now. The seats are inserted and they're fed petrol, oil and other things needed to make them run.

They need fuel to be able to drive off the production line.

The coats of paint receive one final inspection under bright lights. They're so shiny.

Finally, every car off the line has its headlights, brakes and horns tested.

Every single car goes through the procedures to ensure that no errors have been made along the way.

And here's one of the finished models, sat happily in the sun, among some of the 10 wind turbines Nissan has on-site.