Shipworms do not survive in the Baltic Sea; thus shipwrecks there are usually found better preserved than in other bodies of water. The <i>Wasa</i> was an important find, shedding light on 17th-century building techniques. The treatment of the wood with polyethylene glycol was the first major problem in the restoration of the ship. Large sections were sprayed while 12,000 structural wood parts and a large quantity of wooden and leather objects belonging to crew or part of the ship's equipment were treated in closed vats or a specially built furnace for the load of cast iron bullets. The recovery and conservation treatment of the sails is detailed. The choices considered in developing the restoration policy are presented. Drawings of the vessel were prepared subsequent to the restoration. The dock upon which the conservation work has been done was originally intended to be in use for only 10 years and had not been equipped for providing a climate controlled environment; by 1983, a museum design was approved to provide better protection and security for the vessel. The criteria that were to be met by the design are listed.