Eidsvoll Square (Eidsvolls plass) is a square and park in Oslo, Norway. It has been referred to as "the National Mall of Norway".
It was originally a marshy area, but became a park around the same time as buildings were raised in the street Karl Johans gate, and the street Stortingsgata was built in the south, cutting across the marsh. It was preserved as a park because house owners in Karl Johans gate did not want tall buildings on the other side of the street. In 1864 the park was given its current name, inspired by Eidsvoll where the Constitution of Norway was drafted and signed by the Norwegian Constituent Assembly.
In 1956, a plan by architect Arnstein Arneberg was set into motion, creating a decorative pool of water at Eidsvolls plass. Funded by the company Christiania Spigerverk, it was nicknamed 'the nail soup' (Spikersuppa). The pool has a fountain in the middle, and since 1958 a group of trees as well as a statue of deer in the west.