Tjörnin (Icelandic pronunciation: [ˈtʰjœ(r)tnɪn]) is a small, prominent lake in central Reykjavík, the capital of Iceland. Most visitors to the city pass along its shore, as it is situated in the city centre next to the Reykjavik City Hall and several museums. Tjörnin means “the lake” or “the pond”.
Feeding the birds on the lake shores is a popular pastime, so much that it has been referred to as “the biggest bread soup in the world”.
Tjörnin is described as a lagoon next to a barrier beach. The lake’s formation is attributed to the lagoon which was part of a reef that existed at the present location of Hafnarstræti (a city street, “Harbour Street”). This street, which passes through the business section of the city, lies on the southern side of the lake and leads to the gardens. The Vatnsmýri marsh feeds the lake. The outflow from the lake is Lækurinn, previously an open water channel flowing through the city centre, but since 1911 part of the sewage system under Lækjargata. During the winter, the lake usually freezes periodically and is used for ice skating. The average depth is 0.57m (1.9 feet) with the deepest point at 0.8m (2.4 feet). Both banks of the lake are paved and terminate at the Hljómskálagarður (formally known as Tjarnargarður), a well-tended park decorated with statues to the south of the lake. The winding paths are frequented by joggers and cyclists. Notice boards along the shore give daily reports of the numbers of birds on the lake.