Llyn Gwgia is on the Gregynog Hall Estate and is a secluded 25 acre Victorian reservoir. The fishing is for wild brown trout. There is foot access around most of the reservoir and wading is possible well out from the bank. However, caution is needed and a wading staff used at all times.

Fishing is only permitted from a boat in the top bay as marked on the map. There is only one boat at present which is available to book, anglers must bring life jackets and they must be worn at all times.

The venue was once available online with the Fishing Passport, enquires to fish must now be made to Gregynog Hall.