The underground Medieval Museum is ideal to visit in summer days. It was built around an old archeological site that workers discovered while digging dirt for a new parking lot in the 70s. The old Riksdag building needed renovation, and at the same time a time garage for Riksdag members was to be built. Before the garage construction began, archeological investigation was carried out and the results were astonishing. They found remarkable excavations. There were parts of Stockholm's city wall built by Gustav Vasa in 1530. There was also the churchyard of medieval Helgeandshuset cemetery with about 7 tons of skeleton, as well as the Riddarholm ship with cannons, bullets and gunpowder.
These remains represent significant monuments of Stockholm cultural heritage. The museum was opened to general public in 1986, and in 2010 it was opened again, a modern museum with new technology this time. The Medieval Museum tells a story about city’s medieval history, about the life and history of Stockholm and its kings, about everyday life and praise of people, about happiness and sadness of the Middle Ages.