Bláhylur Lake, also known as Hnausapollur, is a beautiful dark blue lake located near Landmannalaugar. This lake is often mistaken for its neighbor Ljótapollur as they look so similar, but Bláhylur is much easier to access.
Being very accessible, it would be a shame not to stop there before starting a day of hiking in Landmannalaugar.
Bláhylur is a maar, a unique type of lake formed in a crater following an explosive eruption, in this case almost 1,200 years ago. Maars form during eruptions when lava comes into contact with groundwater. This is exactly what happened here in 871 when the Bárðabunga and Torfajökull calderas began to awaken.
Located very close to Mount Tjörvafell to the north of the equally beautiful lac Frostastaðavatn, it is quite large, with an area of 30 hectares. Those with a fisherman's instinct will be able to catch a few anglers in these waters, but they are known to be home to an incredible quantity of brown trout so that is your best bet.
Blahylur is named after the blue color of its waters which contrasts beautifully with the ocher flanks of the crater it and the bright green moss that grows on its volcanic rocks.
You can walk along the west flank of the crater, with passages down onto the banks close to the water (and its fish population). At the northern tip of Hnausapollur, the small summit of Hnaussar (758 meters) offers an excellent view of the lake, and this is a great place to capture well-framed photo. You can scale this summit, the walk is relatively short but very steep.
The walk along the west flank and to the top of Hnaussar and back is under 1.6 km and does not take more than 45 minutes.
The lake is only 9 km north of the Landmannalaugar campsite, very close to the 208 North (Fjallabak Nyrðir) trail that cuts right through the heart of the Fjallabak Nature Reserve. Look for the small sign indicating “Hnausapollur” leading down a small trail of a few hundred meters to get to the lake by car.
Hnausapollur is a mountain lake located at an altitude of 570 meters, typical of these highland landscapes, much like Ljótipollur. While not the most popular natural site in the region, it's definitely worth a pit-stop if you are nearby to admire this absolutely superb panorama of striking contrasts.