Mosfellsbær is a town in south-west Iceland, some 12 kilometres (7 miles) east of the country's capital, Reykjavík.
The town of Mosfellsbær is only a 15-minute drive from midtown Reykjavík. The district includes the Leiruvogur cove, which forms part of Kollafjörður fjord. Three rivers empty into the cove: Leirvogsá, Kaldakvísl and Varmá.
Mosfellsbær provides numerous opportunities for outdoor and leisure activities, close to untouched nature. There has been a systematic development of outdoor recreational areas for residents, their guests and tourists.
Often called "the green town", this town enjoys thermal activity and quite a few greenhouses have been built here. Since 1933 it has supplied the capital area with natural hot water for house heating, swimming pools, etc. The mountainous area around the town is ideal for walks and hikes, skiing and fishing for trout and char in the small lakes. The Nobel Prize laureate for literature in 1955, Halldór Laxness (1902–1998), was an honorary citizen of the town. He lived there all his life and based some of his novels on his experiences and impressions of his surroundings.
Source: https://en.wikipedia.org/wiki/Mosfellsb%C3%A6r
Mosfellsbær liggur norðan við Reykjavík.