It was the cattle that first caught my attention. Great, milky beasts with brutal-looking horns and distinctive black ears, they stood in their daffodil-specked surroundings like something from a fairytale.
This wasn't far from the truth, according to Wyn Davies, the warden at the National Trust's Dinefwr Park and Castle, who joined me on a blustery hike around the property's Capability Brown-designed grounds, on the western edge of the Brecon Beacons.
"This spot truly is the historic heart of Wales," he said. "In the 12th century, Dinefwr was a royal capital. There are also the remains of two Roman forts here, and those cows you can see are White Park, a rare breed [inset below] whose connection with this park goes back to medieval times.
"There are all sorts of legends associated with them but one of the best tells of the Physicians of Myddfai," he added. The story goes that in the 12th century a farmer's widow sent her son, Gwyn, to watch over her cattle grazing near a lake called Llyn y Fan Fach in the Black Mountains. One day, Gwyn spied a beautiful woman standing in the water. After much wooing, he finally persuaded her to marry him and she rose from the lake for her wedding leading a dowry of animals, including White Park cattle. Their children became the Physicians of Myddfai.
There was a catch to the deal though – if Gwyn struck her three times, however inadvertently, she would return to the water. When, inevitably, Gwyn's three strikes were out, the lady of the lake fulfilled her promise, wading back into Llyn y Fan Fach with her cattle in tow.
As I finally made an altogether drier retreat towards Llandeilo, the adjacent town, Davies called after me. "Of course, the best way of preserving these rare breeds is to eat them." I took his advice, stopping off at the Salutation Inn to tuck into a post-walk blow-out of locally sourced steak and chips.
The meat on my plate may not have been White Park, but the provenance of the Salutation Inn's menu was important. Llandeilo is enjoying a growing reputation as a centre of sustainability. As well as being part of the Transition Towns movement, which aims to adapt communities to a future of low oil consumption and low carbon emissions, there is also a campaign to bring the slow food movement to the town, promoting locally produced fare and regional cooking.
Much of the delicious, home-cooked tapas at Caffi Salvador (warming cannellini bean mash with sage and garlic, fat lamb chops marinated in lemon juice and coriander or plump grilled sardines), or dishes such as lamb hotpot at the unpretentious Y Polyn gastro pub, a bike ride away, are locally sourced.
By putting an indulgent spin on its sustainable credentials, rather than beating visitors down under a blanket of worthiness, Llandeilo is also currently enjoying a rather unexpected boom as a green tourism destination.
Shopping is one of the obvious attractions, with the town's pretty, multicoloured Georgian and Victorian townhouses home to a wide range of mainly small, independent suppliers.
You don't have to spend a lot to have a good time, though. Great local walks can be found around sights such as Dinefwr Park, 10 minutes on foot from the centre of town, or Carreg Cennen, a ruined 12th- and 13th-century castle perched on a craggy outcrop three miles away. Hop on a bike and, with a bit of effort, the National Botanic Garden of Wales and Aberglasney Garden both make good day trips.
When you're done, you can head home to Llandeilo to sleep on an organic mattress at Fronlas, a stylish and green B&B that has recently opened. A surprisingly grand Edwardian house, hidden on an unprepossessing residential street, Fronlas is thoughtfully run by a young, enthusiastic couple, Eva and Owain Huw.
Turning up there on a damp Friday evening, I was met with smiles and warm-from-the-oven Welsh cakes before being shown to a room that wouldn't have been out of place in Notting Hill. But, if the styling is ultra-contemporary, Fronlas has a caring side, too. A member of the Green Dragon environmental scheme, its carbon footprint-reducing initiatives include electricity sourced from Good Energy, hot water and underfloor heating partly generated by solar panels, organic and locally sourced breakfasts, organic towels and bedding, "A" rated appliances and a comprehensive recycling policy.
Even those organic mattresses are locally sourced. Made by Abaca, which was set up by Llandeilo resident Rhiannon Rowley, it was a response to reports about the negative health effects of fire retardants in conventional mattresses and a way of generating income for local sheep farmers whose flocks had been devastated by foot and mouth disease. The company worked with the Soil Association and wool board to get the process certified. It is now so successful that you can buy its mattresses through John Lewis.
"There is something really special about wool, the smell and the feel of it," said Rowley, explaining the appeal of her mattresses over a coffee. For most guests at Fronlas, there is likely to be a more tangible selling point, though – they're also immensely comfortable.
How to get there
There is a railway station in Llandeilo. For train times and fares call 08457 484950 or go to nationalrail.co.uk.
Double rooms at Fronlas (01558 824733; fronlas.com) start from £80 per night.
The Salutation Inn (01558 823325; thesal.co.uk). Caffi Salvador (01558 822908). Y Polyn (01267 290000; ypolyn.co.uk). Dinefwr Park (01558 824512; nationaltrust.org.uk). Llandeilo general information (llandeilo.org)