Llyn Tecwyn Isaf

This is one of many lakes within the Snowdonia National Park but one of the best for rare dragonflies.  

Opening times, entry costs, facilities and directions

Privately owned – access on road only

To get to the lake, take the A496 from Blanenau Ffestiniog to Harlech, turn off in an easterly direction at Trem-y-Garth, heading towards Bryn Bwbach and Llandecwyn.  Follow this road for approximately 1 mile and the lake is on the right after a cattle grid.  There is parking space along the roadside.  The lake and surrounding land are privately owned and therefore should not be entered without permission.


Things to see

Dragonflies can be viewed from the road running alongside the lake. It has a variety of habitats and you can see species such as Downy Emeralds (only site in North Wales), Keeled Skimmers and Hairy Dragonflies. Also Small Red Damselfly on raised mire at south end of lake.




Top species

Downy Emerald

A rare metallic dragonfly with a hairy thorax.

Main flight period is May to August.

Watch the territorial males patrol the lakes shoreline.

Image by Kentish Plover.



Seasonal Highlights

In May the Hairy Dragonfly is the top insect on the lake.

From June other mature adult dragonflies should be returning to the lake site to breed, such as Keeled Skimmer, and pretty water lilies float the open water.

In late summer the view of the mountains in the background, covered in purple heather, is quite something.


Image by Chris Morriss

Contact Information

Snowdonia National Park Authority
National Park Office
LL48 6LF

T: 01766 770274

Llyn Tecwyn Isaf