In August 1624, a fire raged for three days and reduced medieval Oslo to ashes. Rather than rebuild on the same spot, King Christian IV of Denmark-Norway saw an opportunity: he ordered a brand new city to be constructed on the opposite side of the bay, in the shadow of Akershus Fortress. The new city was laid out with wide streets meeting at right angles — a Renaissance grid designed to stop fire from spreading — and buildings were to be made of stone or brick, not the traditional log construction. He named it Christiania, after himself.

This tour takes you through that planned city, today known as Kvadraturen. Despite centuries of change, the original grid survives. You will walk streets that Christian IV's own surveyors marked out, past some of the oldest surviving buildings in Oslo, from baroque merchant houses to Norway's first stock exchange. The neighbourhood has housed merchants, military commanders, lawyers, bankers and bohemians — and its layered history is visible in almost every façade.