Garreg-ddu Reservoir loop from Elan Valley Visitor Center to Pen-y-Garreg Dam
Garreg-ddu Reservoir loop from Elan Valley Visitor Center to Pen-y-Garreg Dam
4.8
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hikers
Garreg-ddu Reservoir loop from Elan Valley Visitor Center to Pen-y-Garreg Dam
04:16
16.0km
180m
Hiking
Hike a moderate 9.9-mile loop around Garreg-ddu Reservoir in Elan Valley, enjoying stunning reflections and Victorian dams like Pen-y-Garreg
Last updated: February 26, 2026
Waypoints
Start point
Parking
Get Directions
19 m
Elan Valley Visitor Centre
Highlight • Monument
Tip by
251 m
Elan Valley Trail
Highlight (Segment) • Trail
Tip by
6.75 km
Pen-y-Garreg Dam
Highlight • Viewpoint
The Pen-y-Garreg is the third Dam up through the Elan Valley, also to be known as the 'Middle Dam'.
Pen-y-Garreg Dam is unusual in that it houses an access tunnel to the central tower which is lit by apertures in the downstream side of the dam.
The viaduct at Garreg Ddu further downstream does not resemble the other dams since the dam part of the structure is not visible above the water surface in normal conditions. There are atotal of four dams on the river Elan;.
Craig Goch.
Pen-y-Garreg.
Garreg-Ddu.
Caban Coch.
The river Claerwen has the newest and largest, Claerwen Dam followed by the unfinished Dol y Mynach dam.
With the exception of Dol y Mynach all the dams are also accessible by car.
Tip by
14.9 km
Caban Coch Dam
Highlight • Natural Monument
Tip by
16.0 km
End point
Parking
Way Types & Surfaces
Way Types
10.0 km
3.16 km
2.26 km
520 m
Surfaces
5.71 km
5.28 km
4.60 km
299 m
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Elevation
Highest point (300 m)
Lowest point (220 m)
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Weather
Powered by Foreca
Friday 8 May
16°C
6°C
41 %
Additional weather tips
Max wind speed: 19.0 km/h
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This route was planned by komoot.
Frequently Asked Questions
Where can I park to start the Garreg-ddu Reservoir loop?
The best place to start this loop is from the Elan Valley Visitor Centre. There is ample parking available there, making it a convenient starting point for your hike.
How long does it typically take to complete this loop?
The Garreg-ddu Reservoir loop is approximately 16 km (10 miles) long. While the tour data suggests a moving time of around 4 hours and 15 minutes, most hikers can expect to complete the route in about 2-3 hours, depending on their pace and how often they stop to enjoy the scenery.
What is the terrain like on the Garreg-ddu Reservoir loop?
The trail primarily follows the historic Elan Valley Trail, which consists of easily-accessible paths. You'll encounter sections that are paved, gravel, and asphalt. While largely well-surfaced, some parts through woodlands might be narrower, have exposed tree roots, and can be wet underfoot. Sturdy footwear is recommended.
Is the Garreg-ddu Reservoir loop suitable for beginners or families?
Yes, the loop is generally considered moderate in difficulty, with accessible paths suitable for most skill levels. Parts of the trail, especially closer to the dams, are suitable for pushchairs and wheelchairs. It's a great option for families looking for a scenic walk, though some woodland sections require a bit more care.
What are the main points of interest along the route?
You'll encounter several impressive Victorian dams, including the unique Garreg Ddu Dam and the distinctive Pen-y-Garreg Dam, which sometimes offers access to its central tower. The tranquil waters of the Garreg-ddu Reservoir provide stunning reflections, and you can also find the remains of Cwm Elan House Garden Walls, where poet Percy Bysshe Shelley once stayed.
Is the trail dog-friendly?
The Elan Valley Trail, which forms a significant part of this loop, is generally dog-friendly. However, it's always best to keep dogs on a lead, especially around livestock and other visitors, and to follow the Countryside Code.
What is the best time of year to hike this loop?
The trail can be enjoyed year-round. Spring brings new growth and wildflowers, summer offers longer daylight hours, and autumn provides beautiful foliage. On still mornings, the Garreg-ddu Reservoir is particularly stunning with its reflections. If you're interested in stargazing, the Elan Valley is an acclaimed Dark Sky Park, making evening visits special.
Are there any entrance fees or permits required to access the Elan Valley or this trail?
No, there are no entrance fees or permits required to access the Elan Valley or to hike this specific trail. The Elan Valley is freely accessible to the public, though parking charges may apply at the Elan Valley Visitor Centre.
Does the trail intersect other well-known paths?
Yes, the route also passes through sections of the Elan Valley Trail, the Trans Cambrian Way, the Cnwch Wood Nature Trail, and the Nantgwyllt Blue Flow Trail.
Are there any facilities or cafes near the trailhead?
Yes, the Elan Valley Visitor Centre, where the loop starts, offers amenities such as toilets, a cafe, and a gift shop. It's a great place to grab a refreshment before or after your hike.
What should I bring for a hike on this trail?
Given the varied terrain and potential for wet sections, sturdy footwear is highly recommended. Depending on the weather, bring appropriate layers, waterproofs, water, and snacks. Binoculars can enhance your experience for wildlife spotting and enjoying the distant views.