New study ranks three Welsh walks among UK’s top 10 for biodiversity

Amelia Jones

A new study has identified three Welsh walks among the UK’s 10 most biodiverse walking routes, highlighting the country’s rich natural landscapes and the variety of wildlife and plant species found across its countryside and coastal paths.

Walking holiday specialists Celtic Trails used a decade of citizen-science data to rank the UK’s iconic trails by their ecological richness, giving walkers a definitive guide to the country’s most biodiverse routes.

Each walking trail was assigned a Biodiversity Score out of 100, based on factors such as the number of wildlife observations and unique species per kilometre of trail.

According to the study, Anglesey Coastal Path is Wales’s most biodiverse walk, scoring 84.44/100. The Isle of Anglesey Coastal Path falls within a designated Area of Outstanding Natural Beauty (AONB) which covers 95% of the coast. The Coast Path is a circular path around the whole Isle of Anglesey.

It passes through landscape that includes a mixture of farmland, coastal heath, dunes, saltmarsh, foreshore, cliffs and a few small pockets of woodland. This includes a National Nature Reserve (NNR).

The 208km route was found to be home to 1,042 unique species, making it the third highest species count of any trail and an average of five unique species per kilometre. Some of the most commonly spotted species on this trail include the Lesser Black-backed Gull, the Great Cormorant and the Arctic Tern.

Cardiff Bay to Barry Island ranked as Wales’ second most biodiverse walk, and ranked fourth overall in the UK. A relatively flat trail along the coast, heading from Cardiff Bay to Barry Island, passing Penarth, Sully and Barry along the way and offering magnificent views throughout.

The walk packs an impressive 180 unique species into just 23.5km, with House Sparrows, a species in serious national decline, ranking among its most commonly spotted. At 7.66 species per kilometre, it is the most species-dense walk in Wales and one of the most concentrated in the UK.

The Wales Coastal Path from Port Eynon to Mumbles ranked third most biodiverse in Wales and ninth in the UK. This long-distance walk offers panoramic sea views, charming villages, and the chance to explore some of the best beaches in Wales. Ideal for seasoned walkers, this path is perfect for those looking for an all-day adventure filled with nature, history, and local culture.

It stands out for its rare wildlife, with the Bloody-nosed Beetle and Viviparous Lizard among its most frequently recorded species. There were found to be 161 unique species recorded throughout this trail, or 6.1 different species per kilometre, and the walk scored an impressive 71.45/100 overall for biodiversity.

Lisa Sanger, Walking Specialist at Celtic Trails said: “In 2026, we are seeing a shift where hikers are looking for more than just a view; they want to see all the wonderful nature the UK has to offer.

“By analysing a million points of data, we’ve been able to prove that biodiversity isn’t just found in the far-flung wilderness. It’s thriving in our managed valleys and along our coastal fringes as well as along our urban walks. This list is a roadmap for the modern ‘eco-trekker’ who wants to see the UK’s natural world at its most vibrant.”

Top 10 UK Trails for Biodiversity:

1. Cotswold Way
2. St Mary’s Island Coastal Path
3. Anglesey Coastal Path
4. Cardiff Bay to Barry Island
5. Northumberland Coast Path
6. Thames Path
7. Isle of Wight Coastal Path
8. South West Coast Path
9. Wales Coastal Path
10. John Muir Way

You can view the full UK list here.