The Marmara Sea is connected to the Black Sea by the Strait of İstanbul (Bosphorus) and to the Aegean Sea by the Dardanelles, or Strait of Gallipoli (Çanakkale Boğazı in Turkish).
The Bosphorus, which connects the Marmara Sea to the Black Sea, has an important place in the world's maritime transport. The narrowest part of the İstanbul Strait (698 m) is between Anadolu Hisarı (Anatolian Fortress) and Rumeli Hisarı (Rumeli Fortress), and the widest part (3,600 m) is between the Rumeli Feneri (Rumeli Lighthouse) and the Anadolu Feneri (Anatolian Lighthouse) in the north.
The Bosphorus carries the waters of the Black Sea with high water levels to the Mediterranean Sea with the upper stream, and the waters of the Mediterranean Sea with high salinity to the Black Sea with the lower stream. This is advantageous in terms of fishing, but not so much so in terms of marine transport.
Fishing in the Sea of Marmara has been important since ancient times. In 2010, the fish caught in the Marmara Sea accounted for 8.36% of Türkiye's fish production. The Mediterranean monk seal, which used to be spotted even off the coast of İstanbul in the 1950s, today are an endangered species. The Marmara population of these mammals, which are estimated at approximately 600 in the entire the world, live on the Kapıdağ Peninsula and around the islands in the south of the sea. Sharks are caught from time to time in the Marmara Sea and various species of dolphins can also be observed off the coast of İstanbul and in other parts of the sea.
The islands in the Marmara Sea are grouped into the Marmara Islands and Princes’ Islands (Adalar in Turkish), and İmrali Island. In terms of marine tourism, the city of Silivri, the town of Marmaraereğlisi (or Marmara Ereğlisi), the Yalova coasts, and Avşa Island stand out in the region.
The population density especially in İstanbul is very high. İstanbul's international airports are global transport hubs that connect the entire world. Türkiye’s road network is widespread and advanced. The Marmara Sea is Türkiye’s most dynamic sea in terms of human and vehicle transportation. Passenger ferry, fast ferry, and car ferry services are frequent. Health and safety facilities are available at every point.
Lake Kuş or Lake Manyas is an important bird sanctuary in Türkiye. With more than 270 bird species, this unique natural wonder also features a bird-watching tower. Visitors can rent a boat on the lake and enjoy the unique landscape.
Cunda Island is a beautiful island located in the Ayvalık district of Balıkesir province. Also known as Alibey Island, Cunda is the largest of the Ayvalık Islands archipelago and the only one with a settlement. You can reach the island by both boat and car.
The world-famous ancient city of Troy, located in the Hisarcık district of Çanakkale, has a prominent place in history and has been on the UNESCO World Heritage List since 1998.