I've been visiting one of UK's longest beaches for 40 years - it just gets better

Sandwiched between the outstanding UK beauty spots of Pembrokeshire and Gower is a hidden gem that you should not ignore. It's possible you may well zoom straight past it, oblivious to its existence, as you head west or east along the busy M4 and A48 to its more famous neighbours.

But hidden quietly away on the coast of Carmarthenshire (which arguably is better-known for its rolling green hills than its coastline) is a huge area that's one of the best places you could visit anywhere in the country. With hundreds of acres of woodland and one of the longest beaches in the UK, you'll find loads to do to fill your time, whether you're there a day or a week.

Cefn Sidan Sands is a Blue Flag beach with eight miles of golden sand sandwiched between the waters of Carmarthen Bay and the hundreds of acres of woodland and countryside of Pembrey Country Park, just west of the town of Llanelli.

While the beach is arguably the main attraction, there's loads more to do here, including walks and trails, a fantastic adventure playground for kids, mini golf, bike hire and even a toboggan and dri sky slope.

There's a large campsite open between March and October, perfect for resting in after a day on the beach or exploring the enormous park, and a fully licenced restaurant and bar serving salads, pizzas and smaller meals for children (there's also a new pirate ship outside the restaurant for playing on).

Cefn Sidan beach

Arguably the jewel in the crown in thie region, Cefn Sidan beach is eight miles of flat, golden sand. It was the first in Wales to achieve the Blue Flag award for its bathing water. On a hot day in summer, it will be busy but it's so big you'll still find room to set up for the day and there are lifeguards through the summer months.

But there is a dark history to this part of the coast, dating back to a time when it was a major shipping route serving Wales' booming coal and tinplate industries. There are said to be an astonishing 300 ships wrecked under the sand of this beach. And though many of them will have fallen victim to the area's treacherous sandbanks, others were lured to their doom by merciless looters.

Coastal park ranger Emyr Richards said in 2019: "There would be a gang of looters that would actually try to entice the ships on to the sands using false beacon fires. Your ship gets caught in the sands, and it's wrecked, and they come in and plunder the cargo."

One such group of looters was known as "Gwyr y Bwyell Bach" (meaning "the men with the small hatchets"), so called because of the weapons they carried.

"The reasons the hatchets were special was because they had a claw hammer and little hatchet," said Mr Richards.

"And the main reasons for that was to chop off the fingers of victims to get the rings off and to take what they want, breaking into the casks of brandy and fine wine, quite a savage time."

The entire coastline of Wales is dotted with shipwrecks, in fact. A few miles east of Cefn Sidan is a tiny island which is a graveyard of ships - you can still see the twisted metal corpses of ships littering Tusker Rock. Diver James Hedley Phillips has explored more than 30 shipwrecks off the Welsh coast, once recovering a batch of 100-year-old bottles of wine from a wreck which he drank freely before discovering they were worth at least £1,500 each.

There are actually only six "designated wrecks" in Welsh waters and these are given protected status under the 1973 Protection of Wrecks Act. Anyone who visits, films or surveys these sunken vessels needs to get a special licence from the Welsh Government.

On Cefn Sidan, the largest visible remains are at the western end, and belong to a large windjammer that grounded there nearly 100 years ago, called the SV Paul.

In 1925, the ship left Nova Scotia and on October 30 ran into severe gales, losing her sails and anchors and eventually grounding on the sands. It was carrying a cargo of expensive tropical hardwood timber when it grounded.

"Luckily nobody lost their lives in the wreck but the cargo - that's a different story altogether," Mr Richards told BBC Wales. "Many of the houses have got some very expensive tropical hardwood and there were a few garden sheds that were very well-built."

Cefn Sidan's wrecks date back to 1668. They include La Jeune Emma, which was heading to France from the West Indies when it was blown badly off course in 1828. Thirteen people on board died, including Adeline Coquelin, the 12-year-old niece of Napoleon Bonaparte's divorced wife Josephine de Beauharnais, who is buried at a nearby church. After the decline of Llanelli's tinplate industry, the ships stopped coming.

Off the same stretch of coast is the Whiteford lighthouse, an extraordinary structure which is entirely surrounded by the sea when the tide is in. It is the only cast-iron lighthouse in Britain which is "wave-washed". Remarkably, it was occupied and whoever would have lived there would have done so surrounded by wind, waves and one of the most dangerous tidal ranges in the world. It was the lighthouse keeper's job to maintain it and records from 1880 show they got paid £1 a week and stayed up there for two weeks at a time.

Despite how few people would ever have seen them, the lighthouse still features intricate Victorian features, like the railings that surround it. It was decommissioned by the 1930s and has been decaying ever since.

The country park and its key role in British war efforts

Although Pembrey's outstanding natural beauty shines through, there are also signs of the crucial role it has played during darker times in Britain's past. It was once the site of the Pembrey Munitions Factory, where thousands of women sacrificed their health, and often their lives, during World War One. The hair and skin of the women who worked there would turn yellow due to chemicals being used.

Women would suffer burns caused by acid. They would be blinded by vapour. They would suffer seizures, and lost their lives. However, due to the secretive nature of the work their stories are not widely known, .

The factory was built in 1882 by the New Explosive Company but was taken over by Nobel's Explosives Company (founded by the man who the Peace Prize is named after) in 1886 or 1887. With the outbreak of the First World War production was stepped up. At its peak 200 tons of crude TNT was made there every week with a total of 15,000 tons made during the war.

By the end of the war 4,765 workers were employed at the factory, the majority of whom were women. There was so much secrecy around the factory that few records remain. But the diary of a Gloucestershire vicar's daughter named Gabriella West can help shed some light. She had joined a newly formed women's police service where she started working as a sergeant in 1917 and she said her job was to "control the women workers". The extracts from her diary paint a stark picture of what these women endured:

"The girls here are very rough and so are the conditions.

"Their language is sometimes too terrible! But they are also very impressionable.

"Particles of acid land on your face making you nearly mad - like pins and needles but much more so.

"They get on your clothes and leave brown specks all over them.

"They also get up your nose and down your throat and in your eyes so you are blind and speechless."

In a fatal explosion in July 14, 1917, four men and two women were killed. The two women, aged 18 and 19, were named Mildred Owen and Mary Watson. Their funeral was an enormous affair with thousands of people travelling to nearby Swansea to pay their respects. Their coffins were carried on horse-drawn carriages covered in a Union Jack. Sadly, it was not the only fatal explosion at the site - three young women died there in November 1918, days after the end of the war.