Stutthof was a Nazi concentration camp established by Nazi Germany in a secluded, marshy, and wooded area near the small town of Stutthof (now Sztutowo) 34 km (21 mi) east of the city of Danzig in the territory of the Free City of Danzig. The camp was set up around existing structures after the invasion of Poland in World War II and initially used for the imprisonment of Polish leaders and intelligentsia. The actual barracks were built the following year by prisoners.