The mountains around the lake change in character along the route. The Idwal slabs are hard, smooth rocks of rhyolite, a type of lava, and devoid of alpine plants. Their gentle slopes offer good toe and hand holds to would be mountaineers and they have become a popular nursery for fledgling climbers. The dramatic Devil's Kitchen is a deep, dark chasm slicing into the crags at the south-west corner of the lake. The down-folded volcanic rock either side of it is evidence of a former mountain range and its ledges are home to a wide variety of mountain plants, including the rare Snowdonia Lily (Gagea Serotina).

The best view of the ring of mountains is on the west side of the lake. straight across is the massive bulk of Tryfan which can only be summited by rough scrambling. Following the ridge south you can see first Glyder Fach and second Glyder Fawr, both rising high to the left of Devil's Kitchen. On the right is the imposing foothills of Y Garn.

To see wildlife in this area requires patience - and chances are better still with a pair of binoculars. Mountain goats, for instance, are shy creatures, but impressive with their long horns. Peregrine falcons can be seen hovering before swooping swiftly on their prey. Peregrines fight for territory with the ravens which build their huge stick nests on the high ledges. In spring, the common sandpiper can be seen on the edges of the lake, and in summer, flocks of choughs search for food in the grasslands.