It is one of the biggest engineering projects of its kind ever seen in the UK - building the infrastructure that will deliver a regular supply of gas to homes and businesses throughout the country.
LNG - or Liquefied Natural Gas - will be shipped to two huge new depots in Milford Haven and converted back into gas.
From there the gas will be taken via a massive pipeline, through pristine countryside, across the lower half of Wales.
The project, which is near completion, has been dogged by controversy at every stage.
"It wouldn't happen in Surrey." That was the headline in one national paper recently, splashed over a picture of a huge yellow pipeline snaking over the green landscape for miles into the distance.
The inference, of course, is that such a controversial project has only been allowed to happen and has been literally bulldozed through because it is being built in relatively sparsely populated mid Wales.
The reason is simple. We are hopelessly addicted to gas. Britain is the world's third largest consumer of natural gas - an astonishing statistic that thus far has been met by our own North Sea supplies.
With that source running out, and demand still increasing, a long-term supply contract has been signed with Qatar.
The gas will be transported, in liquefied form, to Milford Haven by a new fleet of tankers (cooling the gas reduces its volume by 600 times). The technology is not new but the scale of this contract is unprecedented.
More than 15 million tonnes of gas a year will be delivered to the biggest of the two new depots in Milford, and therein lies the first controversy.
Five storage containers, each bigger than the Royal Albert Hall are going up at South Hook.
The pipeline should be completed by autumn
Despite the public relations spin from the company, there is no doubt that the plant is noisy, disruptive and it is an eyesore.
The Welsh Assembly Government and Pembrokeshire County Council are enthusiastic backers of the deal. They point to the jobs and investment the LNG projects at South Hook and Dragon will bring.
Residents like Tracy Morris say it has brought only despair. "The value of my house has plummeted since this project was approved," she said.
As another huge truck thundered down the narrow country lane, she added: "This used to be a quiet area, now the relentless traffic to and from the site means it's unsafe for my children to play outside."
Safety is certainly the biggest issue further down the line. From South Hook an enormous, 200 mile-long yellow pipeline will carry the gas (now de-liquefied) to the English border and distribution points thereafter.
There is no getting away from it - as it looks now this thing is UGLY - no wonder they wouldn't want it in Surrey. But, and this is a really crucial but, the pipe will soon be buried more than a metre underground.
While the visual impact of the pipe itself is what is grabbing the headlines, arguably of greater concern should be how close this giant yellow tube is passing to homes and communities.
The line of the pipeline is visible from miles around
In other parts of the world, pipes carrying such large amounts of flammable gas are not allowed with a certain distance of built-up areas.
In this crowded island that is a luxury that we cannot afford and National Grid admits there are some "unavoidable pinch points" along the route.
David Mercer is the man in overall charge of the pipeline. "Safety is National Grid's number one concern," he said.
"This project is really just an extension of what we already do. There are thousands of kilometres of high-pressure pipelines all over the country, operating perfectly safely."
There is no doubt that National Grid have taken public concerns to heart. Where it does pass close to homes, the steel walls of the pipe are made extra-thick, just in case.
Also, rather than stirring up further controversy trying to take a direct route through the Brecon Beacons National Park, the pipe largely skirts around the northern edge of one of Wales' most beautiful regions.
The pipe should be finished by the autumn, gas could be flowing from those five Albert Halls in Milford Haven pretty soon thereafter.
Whichever way you look at it, this multibillion pound venture is an impressive piece of engineering.
But, as one sceptic asked: "Do we really need it?"
Some environmental economists argue that with energy recovery from existing power sources and increasing diversification in renewables, we should not be going down the LNG route.
Then again, we all love gas don't we?