The Stock Exchange Old Stock Exchange is a building on Castle Island in the center of Copenhagen, Denmark. It was built by Christian IV from 1619 to 1640 and is the oldest stock exchange in Denmark. It is particularly famous for its dragon-shaped spires, which are 56 meters high, wrapped around the tails of four dragons. Red brick walls and green roofs are intrigued by the minarets, and together with the Christianburg Palace, it becomes the most conspicuous building on the island of Castle in the port area of Copenhagen.