The Royal Arsenal Museum is worth a visit even for those who aren't fans of weaponry. The collection is kept in Christian IV's original arsenal building, which has an arched hall that, at 156 meters long, is one of the largest in Europe. There are massive numbers of swords, guns, war carriages, and cannons, spanning several centuries of warfare, including many that are elevated to art, with intricate inlays of jewels and precious metals. Don't miss the V-1 flying bomb from World War II, an interesting contrast to the older weapons. Admission is free.