Highlight • Lake
Clywedog Dam
Hiking
4.7
(16)
The Clywedog Dam is an impressive concrete buttress dam located near Llanidloes in Powys, Wales, forming the expansive Llyn Clywedog reservoir. Situated in the scenic upper Clywedog valley, this significant landmark stands at an elevation of approximately 314 metres, playing a crucial role in regulating the flow of the River Severn. It is a prominent feature within the beautiful Mid Wales landscape, close to the Cambrian Mountains.
Visitors are consistently captivated by the sheer scale and engineering marvel of the Clywedog Dam. Many describe it as an absolutely incredible and huge structure, noting its status as the tallest concrete dam in Britain, standing 72 metres high and spanning 230 metres wide. The mammoth body of water it holds is a testament to its primary purpose: to control water levels and prevent flooding in the River Severn valley, a function that deeply impresses those who visit.
Before heading out, it's helpful to know that the area around Llyn Clywedog features steep-sided valleys and a variety of trails suitable for walking and cycling. The site is accessible all year round, with car parks available for convenience. While the terrain can be varied, there are numerous viewpoints and picnic areas, making it a family-friendly destination. Consider appropriate footwear for walking trails and be prepared for changing weather conditions typical of the Welsh uplands.
The Clywedog Dam and Llyn Clywedog offer a range of activities throughout the year. It's a popular spot for scenic walks and cycling, including a well-regarded 15-mile circular drive around the lake. The Glyndŵr's Way National Trail also passes through the area, providing longer walking routes. Fly fishing for brown and rainbow trout is a leading activity on the reservoir, and sailing is also available. Wildlife enthusiasts can enjoy spotting buzzards, red kites, and even ospreys, especially during breeding season.
A standout experience for many is exploring the base of the dam, where the fascinating ruins of the Bryntail Lead Mines offer a glimpse into the region's industrial heritage. The dam itself, with its unique curved design, is an impressive sight, particularly when water is released. Hikers often appreciate the panoramic views from various viewpoints around the reservoir, which provide excellent photo opportunities of the vast lake and surrounding Hafren Forest.
Whether you're interested in exploring the walking routes, enjoying a family-friendly cycle, or simply taking in the impressive views, the Clywedog Dam area has much to offer. You can discover a variety of trails for hiking and cycling, from gentle strolls to more challenging routes around the lake. Use komoot to plan your visit and find the best walks in the Clywedog Dam area, ensuring you make the most of this unique Welsh landmark.
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October 22, 2025
October 28, 2023
Hiking
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Nearby routes
Best routes near Clywedog Dam
4.0
(11)
63
hikers
5.21km
01:35
160m
160m
Easy hike. Great for any fitness level. Easily-accessible paths. Suitable for all skill levels.
4
hikers
5.30km
01:39
200m
200m
Easy hike. Great for any fitness level. Easily-accessible paths. Suitable for all skill levels.
5.0
(1)
4
hikers
11.3km
03:17
290m
290m
Moderate hike. Good fitness required. Easily-accessible paths. Suitable for all skill levels.
Details
Informations
Elevation 310 m
Weather
Powered by Foreca
Monday 15 June
19°C
13°C
30 %
Additional weather tips
Max wind speed: 24.0 km/h
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Frequently Asked Questions
Are there specific walking routes around Llyn Clywedog, and what is their difficulty?
Yes, there are several walking routes around Llyn Clywedog. While the intro mentions a 15-mile circular drive, there are also marked hiking trails. The Glyndŵr's Way National Trail passes through the area, offering longer routes. For a full circular walk around the lake, be prepared for a significant distance, as the reservoir itself is about 9.5 km (6 miles) long. Terrain can be varied with steep-sided valleys, so some routes may be moderately challenging. It's best to check specific trail details for elevation and length before you go.
Is Clywedog Dam suitable for a winter hike, and what are the trail conditions like then?
The Clywedog Dam area is accessible all year round, making winter hikes possible. However, conditions can be challenging. The Welsh uplands are prone to changing weather, so expect colder temperatures, potential ice or snow, and muddy trails. Always wear appropriate waterproof footwear and warm clothing. Check local weather forecasts before setting out, as some higher or more exposed paths might be less accessible in severe winter conditions.
What are the parking options at Clywedog Dam, and is there any public transport available?
Car parks are available around the Llyn Clywedog area, offering convenient access to the dam and reservoir. While the intro confirms parking availability, visitor tips suggest that parking can fill up quickly, especially during peak seasons or busy weekends. Arriving earlier in the day is often recommended. Public transport options directly to the dam are limited; visitors typically reach the area by car, often from nearby Llanidloes.
Are dogs allowed on the trails around Clywedog Dam, and are there specific dog-friendly options?
Yes, the trails around Clywedog Dam are generally dog-friendly, making it a great place to explore with your canine companion. However, it's crucial to keep dogs under close control, especially given the presence of wildlife like buzzards, red kites, and ospreys, as well as potential livestock in surrounding areas. Always follow the Countryside Code, pick up after your dog, and be mindful of other visitors.
Are there any cafes, pubs, or accommodation options near Clywedog Dam?
While the immediate vicinity of Clywedog Dam focuses on natural and historical attractions, the nearby town of Llanidloes offers a range of amenities. You'll find cafes, pubs, and various accommodation options there, from guesthouses to hotels. It's a good base for exploring the reservoir and the wider Cambrian Mountains area.
Can I go wild swimming in Llyn Clywedog?
Llyn Clywedog is a reservoir primarily used for water regulation and is also a leading fishery. While there isn't official guidance promoting wild swimming, it's generally not recommended due to cold water temperatures, hidden underwater hazards, and the operational nature of the reservoir. For safety, it's best to enjoy the water from the shore or through permitted activities like sailing and fishing.
What are the best viewpoints around Clywedog Dam for photography or scenic appreciation?
There are numerous excellent viewpoints around Llyn Clywedog. The main viewing area at the dam itself offers panoramic views of the reservoir and the impressive structure. The 15-mile circular drive around the lake provides various pull-offs and elevated spots for stunning vistas of the water, surrounding forests (like Hafren Forest), and the Welsh landscape. The area near the Bryntail Lead Mines also offers a unique perspective of the dam with historical context.
What other activities are available besides walking and cycling at Llyn Clywedog?
Beyond walking and cycling, Llyn Clywedog is a popular destination for fly fishing, stocked with brown and rainbow trout. The Clywedog Sailing Club also offers sailing opportunities on the reservoir. Wildlife watching is another major draw, with regular sightings of buzzards, red kites, and breeding ospreys (often viewable via webcam). Exploring the ruins of the Bryntail Lead Mines at the base of the dam provides a fascinating historical insight.
Is Clywedog Dam wheelchair accessible?
While the general terrain around Llyn Clywedog features steep-sided valleys and varied trails, some areas may offer better accessibility. The main viewing platforms at the dam itself and certain picnic areas might be accessible. However, many of the walking trails are unpaved and can be uneven, making them challenging for wheelchairs. It's advisable to check specific route conditions if accessibility is a primary concern.
What is the history behind the construction of Clywedog Dam?
The Clywedog Dam was constructed between 1963 and 1967, following an Act of Parliament in 1963. Its primary purpose was to regulate the flow of the River Severn, preventing winter flooding and maintaining summer water levels for the West Midlands. The project involved flooding agricultural land and several farms, leading to local opposition. Notably, construction was delayed in 1966 by a bomb detonation, suspected to be politically motivated. It stands as a testament to significant engineering and historical context.
Are there any unique natural features or wildlife to look out for at Clywedog Dam?
Llyn Clywedog is rich in both natural beauty and wildlife. The reservoir itself, nestled in steep-sided valleys, is a striking feature. Keep an eye out for diverse birdlife, including regular sightings of buzzards and red kites soaring overhead. A significant highlight is the presence of breeding ospreys, which have used a dedicated nest platform since 2014. The surrounding Hafren Forest also adds to the area's natural appeal.