Wikipedia's brief article on the Reykjavik City Hall or Radhus (
visit link) informs us:
Ráðhús Reykjavíkur' (English: Reykjavík's City Hall) is situated by the Tjörnin in Reykjavík. It houses the offices of the mayor of Reykjavík, a café and a large 3D map of Iceland. It is sometimes used for art exhibitions.
The building was constructed in 1992 following an international competition won by architects Studio Granda."
It is located in the City Center on a lake and beside a park....not far from the National Parliament (Althingi).