The Dwyryd and Glaslyn Estuaries unite to form one of the most unspoilt large estuaries in Cardigan Bay. Ironically its present form really originates from the industrial boom in the nineteenth century and the rapid development of Porthmadog and Penrhyndeudraeth.
William Madocs built the cob, which cuts across the Glaslyn Estuary, in 1811 to reclaim a large portion of Traeth Mawr from the sea. Slate from Ffestiniog and Llanfrothen was brought in boats along the Dwyryd and later by the Ffestiniog Railway, built in 1836, and then the Gorseddau and Croesor Tramways (1856 & 1864). By 1873 over 117,000 tonnes of slate was exported annually from Porthmadog in more than a thousand ships.
Penrhyndeudraeth was built on land reclaimed from the saltmarshes in the late nineteenth century and most of the inhabitants depended on the Cooke’s Explosives works for their livelihoods. Strange that such an industrial landscape should now be a haven for wildlife. Cooke’s Explosive works is now a nature reserve managed by North Wales Wildlife Trust and important for its oak woodlands and Pied Flycatchers; heaths and nightjars; and pools with Emperor Dragonflies. The former explosives stores are home to seven species of bat.
The sand flats and salt marsh are important winter wildfowl feeding grounds. The numbers of over wintering Pintail are nationally significant. Otters and Water Voles use the estuary’s waterways. And the lower shore muddy gravel is the home of Sand Gaper Clams and Bristle Worms.
The area is renowned for Ospreys which have bred at Pont Croesor since 2005 and whose hunting activities in the estuary make an impressive spectacle to watch.