A 15-minute bus ride from central Reykjavík lies Elliðaárdalur Valley, a large green, public space. It's a very popular destination with the locals for all sorts of outdoor activities, including jogging, biking, walking, horseback riding, fishing, and playing.
Through the valley one of Iceland's best salmon-fishing rivers. Fishing is not allowed for everyone, to get a permit one will have to join Reykjavík's Fly-fishing Club and partake in an annual lottery. However, everybody is welcome to navigate the banks of the river, and perhaps see a hunter skillfully catch a salmon.
Elliðaárdalur is one of the few habitats of wild rabbits. Like most wild mammals in Iceland, these were originally brought here for farming or as pets. Some got loose, and somehow manage to survive the Icelandic winter.
In the middle of the valley, an old power station produces some of Reykjavík's green energy. If you walk past it, you will soon find Árbæjarlaug swimming pool. Also, located in the valley is Árbær Open Air Museum.