UFOs and a Tardis - why unusual holiday stays are booming

Travel journalist Simon Calder said the shift reflects a much bigger change in traveller priorities.

"There's a divergence in what travellers want," he said. "Sometimes they're after a low-cost hotel with decent Wi-Fi. But for other trips they want somewhere with character and stories to tell."

Calder said this wider impact is significant: "Inbound tourism is the most valuable element of any economy - it's the closest thing you can get to free money, so exciting enticements are just what Wales needs."

The origins of how the Pembrokeshire site came about, however, were far more modest.

The couple initially bought four acres of land with plans to restore the 17th Century mill and built a treehouse for personal use in the meantime. The shift towards hospitality came later, as the "glamping" trend began to emerge.

"I was looking for something different," Johnson says. "I fancied building a UFO, but doing it from scratch would have been too expensive."

Instead, he repurposed a fibreglass structure originally used during the 2012 London Olympics to hide generators.

"I saw it on eBay and thought that's an interesting shape... I can do something with that."

The transformation that followed was largely improvised.

"I didn't draw anything out on paper," he said.

"It was all in my head. I'd sit in the hot tub in the evening planning it, then try things out the next day."

The process was not without difficulty. Engineering a functioning drop-down door, designed to mimic cinematic spacecraft entrances, proved particularly challenging.

"It was a hell of a task...a lot of trial and error," he recalled.

The final result leans heavily into theatricality.

Guests enter via a descending ramp, accompanied by lighting effects and smoke, while hidden sound features add unexpected moments of surprise.

One installation, triggered by flushing the toilet inside the Tardis, emits the sound of the fictional time machine taking off.

"I don't tell anybody," he said, "then I ask them afterwards what they thought - it makes them jump out of their skin."

Such details are central to the experience, but so too is the setting.

Built in 2017, the futuristic appearance continues to attract attention. Passing helicopters have reportedly diverted from routine routes to take a closer look, while guests often arrive with little idea of what awaits them.

Johnson said: "We quite often get people who don't tell their children where they're going."

"Then they walk up the path and suddenly see it, and the kids just run wild, completely excited."

For those wanting to stay somewhere away from the norm, there are choices around the UK ranging from lighthouses and windmills to prison cells and tree houses.

Wilson said that in Wales he had seen a steady rise in 'hobbit hole' style houses, as well as converted grain silos, glamping pods situated either by or over water, converted horse vans and other former vehicles.

Amongst some of the most notable: "We even have a cabin in the form of a dragon's eye, two UFOs and two woodland 'conkers'"

But when asked why people were seeking out unusual accommodation, he said the buzzword was "experiential".

"People want to feel more from their holidays, often choosing the accommodation itself these days over the location.

"It's an interesting shift in the market dynamics, and one that we noticed 10 years ago when we launched the business."