Heading east along the Norrström, the next bridge is the Riksbron (roughly, the "State bridge").
This links Norrmalm to Helgeandsholmen, a small island which is home to the Swedish parliament building.
A bridge was proposed at this location in 1712, but nothing was built until 1907, when a steel truss structure was erected. This was replaced in 1931 by the bridge which stands there today, designed by engineers Axel Björkman and K A Wickert with architect Ragnar Östberg (who was also involved in the Stadhusbron).
The bridge is a 44m long reinforced concrete arch, with a hinge at the crown. It's a simple, elegant design, helped by the shallowness of the arch and the inclusion of only limited detail to break up the flatness of the concrete. The metal parapets are attractive and lightweight, and it's a significantly better looking bridge than the next one I'll be sharing here.