How green is the valley Welsh garden becomes thriving success story

Amid the gentle hills of Carmarthenshire's Tywi valley, the domed glasshouse of the National Botanic Garden of Wales sparkles from miles away.

- Bethan McKernan

Designed by Sir Norman Foster, when the garden opened in 2000 it was the largest single-span glasshouse in the world, set among 230 hectares (570 acres) of gardens and a nature reserve - but today, the most special part of the site is actually a modest hillside where Welsh black cattle graze.

At this time of year, there is little to see in the organically managed pasture other than the cows. But in autumn, this field boasts 23 species of colourful waxcap mushrooms - many of which are endangered.

"I've been coming here since I was a teenager and one of the reasons I love working here now is because you can see the hard work paying off. Some of the rarest mushrooms and wildflowers here populate more and more of the site every year," says Dr Kevin McGinn, the garden's chief botanist.