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Mountain biking trails

Carmarthenshire

Llanfair-Ar-Y-Bryn

Twm Siôn Cati's Cave – Llyn Brianne Dam Crossing loop from RSPB Gwenffrwd-Dinas

Mountain biking trails

Carmarthenshire

Llanfair-Ar-Y-Bryn

Twm Siôn Cati's Cave – Llyn Brianne Dam Crossing loop from RSPB Gwenffrwd-Dinas

Moderate

2.0

(2)

36

riders

Twm Siôn Cati's Cave – Llyn Brianne Dam Crossing loop from RSPB Gwenffrwd-Dinas

02:51

28.5km

700m

Mountain biking

Moderate mountain bike ride. Good fitness required. Suitable for all skill levels. The starting point of the route is right next to a parking lot.

Last updated: June 17, 2026

Tips

Includes a very steep uphill segment

You may need to push your bike.

After 9.68 km for 1.01 km

Waypoints

A

Start point

Parking

Get Directions

1

128 m

Twm Siôn Cati's Cave

Highlight • Viewpoint

Twm Siôn Cati's Cave Is Situated within the RSPB Gwenffrwd-dinas Nature Reserve, the cave is reachable by a walk through woodlands, alongside a river bank and a steep climb to the top of Dinas Hill.

Tip by

2

2.54 km

Llyn Brianne Dam Crossing

Highlight • Bridge

Llyn Brianne is a spectacular reservoir at almost 300m (990ft) above sea level. It is Wales second largest reservoir by volume and is contained by a 91m (300ft) stone-built dam, which is the largest of its kind in Europe.

Tip by

3

5.17 km

Path from Troed Rhiw to the Dam

Highlight • Trail

4

13.2 km

Capel Soar y Mynydd

Highlight • Religious Site

Capel Soar Y Mynydd is the most remote chapel in Wales. An invaluable spot to find some shelter on longer trips!

Tip by

17.9 km

Dinas

Ruins

B

28.5 km

End point

Parking

Way Types & Surfaces

Way Types

12.8 km

8.69 km

3.61 km

3.46 km

Surfaces

16.9 km

4.41 km

3.64 km

3.46 km

176 m

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Elevation

Elevation

Nothing selected – click and drag below to see the stats for a specific part of the route.

Highest point (440 m)

Lowest point (170 m)

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Weather

Powered by Foreca

Tuesday 16 June

18°C

12°C

28 %

Additional weather tips

Max wind speed: 19.0 km/h

to get more detailed weather forecasts along your route

Comments

December 26, 2021,Llyn Brianne Loop from Strata Florida

Absolutely NOT a mountain bike trail, it's half bridleway or hiking, other half mountain track. Great views at times, but a lot of work.

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