b" I n Llyn Tegid, the largest natural lake in the park, lives another Snowdonia rarity, the Gwyniad, a unique sub-species of the European white fish, trapped in the lake at the end of the last Ice Age, 10,000 years ago. History and culture iseverywhere in Snowdonia and the Welsh language is the mother tongue of 65 percent of the population. You're sure to see and hear the Welsh language in use when you visit. Snowdonias landscape illustrates the history of the area through Stone Age burial chambers, Roman forts, churches, castles, slate quarries and other industrial works. I ce Age activity has done much to shape the landscape in Snowdonia. The glaciers that were at their peak 18,000 years ago in Snowdonia scoured out great U-shaped valleys including Llanberis and Nant Gwynant in the north and Tal-y-Llyn in the south.31"