Comprised of the northeastern part of the Island of Cyprus, Northern Cyprus is recognized only by Turkey, as the international community recognizes it as part of the Republic of Cyprus. As such, the island is divided by the 'Green Line,' a demilitarized UN buffer zone, which is most apparent in the city of Lefkoşa/Nicosia (depending on which side you're on, there's a different name). A passport is required to pass the checkpoints, but that is all. The most popular attraction in North Cyprus is the town of Girne, where many of the hotels are located. Kyrenia Castle is a 16th-century Venetian castle, and together with Kyrenia Harbour, are popular spots to visit. The Shipwreck Museum is nearby, with remnants of a 4th-century Greek vessel and its cargo. St. Hilarion Castle is also worth visiting, as it's built into the side of a mountain. There is also Soli, remnants of a Greek city from the 6th century, as well as Persian ruins from the 5th century at Vouni Palace. The ancient city of Salamis and the Royal Tombs are other archaeological highlights, as well as St. Barnabas Monastery.