Llyn Conglog
Llyn Conglog

Blaenau Ffestiniog, Gwynedd, Wales

About this water

Brown trout
OS Grid Ref: SH 67401 47310
Latitude: 53.00663717651
Longitude: -3.9776287748

A short distance from the summit of Allt Fawr lies Llyn Conglog. At 2000 feet, this remote eight-acre lake is worth a visit for the views alone.

During the winter of 1947 a severe frost was thought to have killed its population of trout. During the 1990's, a fry restocking program helped to establish a healthy population of brown trout. Today, the lake is an excellent brown trout fishery with fish of 1lb caught regularly and 4lb fish landed every season.

At this altitude the lake takes time to warm up and will fish better between July and September. In those balmy summer evenings you could witness some frantic sedge fishing. Large sedges inhabit this water so don't forget the dries. The east bank is the most accessible and features a marginal shelf that is crying out for a team of wet flies. Most of the west bank is high but there are areas you can climb down to the water's edge. Cast your flies tight into the high bank where the fish lie waiting to gobble up clumsy terrestrials or your Coch-y-Bonddu.

It'll take you about two hours to walk up to Llyn Conglog. Park at the car park at Tanygrisiau and follow the path through the old slate mine. It can be eerie walking through the abandoned buildings on a grey afternoon. Walk up the path leaving this industrial past behind you, across the dam at Llyn Cwm Corsiog and in a north-easterly direction towards Conglog.

Remember to take an OS map, warm clothing and waterproofs. The weather can change quickly and will be very different to the clement weather you may or may not experience at the car park.

Water map


Permission & Tickets

Permits can be purchased online and from the following locations:

Siop Antur Stiniog,
Units 1 And 2 High Street,
Blaenau Ffestiniog.

Brethyn Blaenau,
33 High St,Blaenau Ffestiniog.
01766 831536

Siop Dewi
14-15 High St, Penrhyndeudraeth
LL48 6BN
01766 770266

Swyddfa'r Post,
Market Place.
Blaenau Ffestiniog.
01766 830115

Contributed by

Steven Cook

Wind enthusiast, tippet collector and leader length obsessive. Steven knows only trout. His education was hindered by his lack of attention to anything that wasn't trout fishing. If you can find him he's usually at the front; over the furthest headland, bay or peninsula, pulling a team of wets and whistling the theme to The Littlest Hobo.

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