Christian IV's initial intention to build a modest summer retreat in 1606 gave way over time to his building frenzy and the edifice became a genuine castle. The most advanced techniques of the era were used here: bathrooms with running water, and a drawbridge operated from the winter salon. In 1710, the palace ceased to be a royal residence as Frederik IV considered it too small. It has been open to the public since 1833 and houses the Crown Jewels.