Wikipedia
Årungen is a lake in Norway in the municipality of Ås about south of Oslo which is notable for being an environment containing microscopic creatures called collodictyons. Norwegian scientists have been studying the creatures for two decades and speculate that they may be one of the oldest known organisms, and may provide clues about the origins of life. One kilometre south of the lake lies the Norwegian University of Life Sciences.
The lake's elevation is 33 meters above sea level and it straddles both Ås and Frogn municipalities of Akershus county. The surface area is . Its drainage basin is Østensjøvannet and a number of small fords. It drains into Årungselva river northward to Bunnefjorden. The eastern side of the lake has been adapted with strolling paths and picnic areas.
The water is shallow and rich with nutrients, and inflow from agriculture annually causes blooms of toxic blue-green algae. Nevertheless the lake is rich in fish life, with northern pike, European perch, Common Roach and European eel. The water quality has improved in recent years. The wetlands area at the southern tip is an important part of the local fauna and flora.
Årungen is also home to the Norwegian national center for rowing and paddling. Årungen was host to the 1993 World Rowing Junior Championships.