States of] Jersey, Channel Islands are what's left of the medieval Dukedom of Normandy . These islands are on British-owned land, and were occupied peacefully in World War II, surrendering in 1945. The Channel Islands are not part of the United Kingdom. The inclusive population of the islands is approximately 91,000 people. Jersey is best known for the underground fortress system where their entire army division could be protected from air of sea attack. One of those fortresses became the Underground Hospital where two German civilian contractors began digging, using forced and slave labor. The hospital wasn't finished, but it became a triage center. The tunnels were said to be ingenious in design, as the whole complex was built on a hill that lets rain slope and keeps the tunnels dry. The system still works, and for their age, the tunnels are still quite dry. The complex has been restored as a museum of the German Occupation.