Lakes around St. Harmon are primarily large reservoirs located in the nearby Elan Valley, a region in Powys, Wales. While St. Harmon itself is situated on the Afon Marteg river, the surrounding area is known for its significant man-made lakes. These reservoirs, often mistaken for natural lakes due to their size, contribute to the region's landscape. The area provides opportunities for outdoor activities around these water bodies.
Last updated: June 16, 2026
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Built primarily to regulate the flow of water in the River Severn, the Clywedog Dam is an impressive sight. It's the tallest concrete dam in Britain, at 236 feet (72 m) high, while it's also 750 feet (230 m) wide. There are two marked hiking trails on the reservoir.
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A good way into the valley. A flat out gravel surface that winds around the dams for miles
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Brilliant place to Cycle , either on road or Trails ...just Brill !!!
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Elan Valley is a mountain bikers dream. A mix of natural trails that follow the reservoirs and crest the lofty tops of each valley. There's also a great trailhead in the middle of the valley at Nantgwyllt for some great flowing singletrack.
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Pen y Garreg Dam third of the Elan Valley Dams, also known as the middle dam. This dam houses an access tunnel to the central tower which is lit by apertures in the downstream side of the dam. Height - 123 ft above river bed. Beautiful scenery a great ride around this area.
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Llyn Clywedog was the Tallest in the British Isle built purposely to control the level of water to help prevent any future flooding from the source of the River Seven. By Building this absolutely incredible huge 6 mile long dam, one that was the tallest in the British isles, which is amazingly huge in actual size all around! This mammoth body of water is solely to take the huge pressure off the constant mass of floods which would fill up and submerge the surrounding valleys! At the foot of the dam there is a remains of a old lead mine! All structures you can see standing still today. HIGHLY RECOMMEND
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The 'lakes' around St. Harmon are primarily large, man-made reservoirs located in the nearby Elan Valley. These impressive water bodies, often mistaken for natural lakes due to their size and scenic beauty, were constructed to supply drinking water, particularly to Birmingham. They are integral to the region's landscape and offer various outdoor activities.
Among the most notable are Caban-Coch Dam and Reservoir, which is the second largest in the valley and features an impressive dam. Another significant site is Pen-y-Garreg Dam, also known as the 'Middle Dam', notable for its unique access tunnel. Further afield, the Clywedog Dam is an impressive sight, being the tallest concrete dam in Britain.
Yes, the area is excellent for cycling. The Elan Valley Trail is a popular cycle path that leads from Rhayader around the reservoirs, offering beautiful views. Additionally, the Elan Reservoir Gravel Track provides a scenic gravel ride with stunning views. For more challenging rides, you can explore various MTB trails around St. Harmon.
Absolutely. The region offers several hiking opportunities. For instance, the Clywedog Dam area has two marked hiking trails. You can find a variety of routes, from easy to difficult, by exploring the hiking guide for St. Harmon, which includes trails like the Afon Elan Suspension Bridge loop.
Yes, several areas are suitable for families. The Pen-y-Garreg Dam and Clywedog Dam are both considered family-friendly. The Elan Valley Trail is also a great option for family cycling or walks, offering relatively flat paths around the reservoirs.
The Elan Valley and its reservoirs are beautiful year-round. Spring brings fresh greenery and blooming wildflowers, while summer offers warmer weather ideal for cycling and longer walks. Autumn is spectacular with vibrant foliage, and even winter can be atmospheric, though some facilities might have reduced hours. Always check the local weather forecast before your visit.
The Elan Valley is rich in wildlife. You can often spot various bird species, including red kites, buzzards, and peregrine falcons soaring above. The reservoirs and surrounding woodlands are also home to otters, badgers, and a variety of smaller mammals and insects. It's a great area for nature observation.
Yes, the trails around the reservoirs are popular for running. The Elan Valley Trail offers scenic routes suitable for various distances. You can find more detailed running routes, including loops around the dams, in the running trails guide for St. Harmon.
Many spots offer stunning views. The Elan Reservoir Gravel Track is known for its breathtaking vistas. The dams themselves, such as Caban-Coch Dam and Pen-y-Garreg Dam, provide impressive perspectives of the engineering marvels and the expansive water. The entire Elan Valley Trail also offers continuous scenic beauty.
Yes, there are various parking areas available throughout the Elan Valley, particularly near visitor centers and key attractions like the dams. For instance, the Elan Reservoir Gravel Track mentions parking availability. It's generally well-signposted, making it convenient to access the trails and viewpoints.
Visitors frequently praise the stunning natural beauty and the tranquility of the Elan Valley. Many appreciate the impressive engineering of the dams, like Caban-Coch Dam, and the excellent opportunities for cycling and walking on trails such as the Elan Valley Trail. The peaceful atmosphere and scenic views are consistently highlighted as major draws.


Still not found your perfect lake around St. Harmon? Check out the guides of these regions to see even more beautiful places.