Updated
Marchlyn Mawr
Reservoir
Marchlyn Mawr reservoir is a high level lake in Snowdonia behind Elidir Fawr mountain. It is used as the high level water source for Dinorwig power station, a closed-loop pumped storage hydroelectric generating facility. It is said that nearby lies the cave containing Arthur's treasure, a source of bedazzlement to the wanderer who sees it, and of disaster to the pilferer who touches it.
Interactive map not available
Weather at Marchlyn Mawr
Sponsored gear checklist
Pack smarter for Marchlyn Mawr
Useful gear categories for this kind of water spot. These links open Amazon search results so you can compare current options.
As an Amazon Associate we earn from qualifying purchases.
Frequently asked questions
- Where is Marchlyn Mawr?
- Marchlyn Mawr is a reservoir in Wales.
- Can you swim at Marchlyn Mawr?
- There is no fixed answer for Marchlyn Mawr: whether it is safe to swim there on a given day depends on the water temperature, recent rainfall, and any advisories posted at Marchlyn Mawr in Wales. Check current water conditions before you go, and follow posted signs and local guidance.
Advertisement
Visitor Reviews
Be the first to share your experience here
Join our community to share your water adventures
Earn badges as you share your experiences!
No reviews yet — share what you know
Been here? A quick note helps the next visitor plan their day. Handy things to mention:
Best Times to Visit
- ›Check for boat launch facilities and fees
- ›Obtain required fishing licenses before arrival
- ›Be aware of lake-specific regulations and restrictions
- ›Monitor water quality reports before swimming
Location & Contact
Wales
</> Embed this location on your site
Paste this snippet into your website to show a live badge for Marchlyn Mawr — free to use with the included credit link.