Roskilde is the main city in Roskilde Municipality, Denmark on the island of Zealand. It is an ancient city, dating from the Viking Age. With a population of 46,701 the city is an economic center for the region. Roskilde has a pedestrian street running down the center of the city, with many shops, restaurants, and cafes. The Viking Ship Museum in Roskilde is the Danish national museum for ships, seafaring and boatbuilding in the prehistoric and medieval period. Around the year 1070, five Viking ships were deliberately sunk at Skuldelev in Roskilde Fjord in order to block the most important fairway and to protect Roskilde from enemy attack from the sea. These ships, later known as the Skuldelev ships, were excavated in 1962. They turned out to be five different types of ships ranging from cargo ships to ships of war. The Viking Ship Museum overlooks Roskilde Fjord and was built in 1969 especially to exhibit the five newly-discovered ships.