THE MYSTERIOUS HISTORY BENEATH THE SEAS OF ISTANBUL

 Istanbul's history isn't just found on land; there are also important cultural sites underwater.

 Over time, earthquakes, storms, the rise of the sea level, and ships that sank have all added to the underwater cultural heritage of Istanbul.

Between 2004 and 2013, the Directorate of Istanbul Archaeological Museums did rescue excavations at the site of the Yenikapi Marmaray and Subway Projects. These excavations led to the discovery of the Port of Theodosius (Portus Theodosiacus), which was one of Constantinople's biggest ports during the Byzantine Period. After the 9th century, the Port of Theodosius was filled with sand and gravel carried by Lykos, which is now called Bayrampasa Stream. The alluvial deposit that covered the port kept 37 sunken ships and a lot of small artifacts in great shape. The underwater objects were found during the excavations. They are also the most sea equipment from the Early Middle Ages that has ever been found in one place.

Due to a natural disaster, the Vordonisi Island, which is one of the best places to dive in Istanbul and is mentioned in old books but wasn't found until recently, stayed under the Marmara Sea. The island is thought to have stayed under water because of a big earthquake that happened in the 1100s. An underwater survey done in 2016 found that the Monastery Rocks, which are 1 km from the shore between Dragos and Kucukyali, led to the Vordonisi Island.

As part of the North Eastern Marmara underwater research, these investigations also took pictures from the air of what was left of the exile monastery of Patriarch Phoitos. Surface operations also found a sunk ship with a piece of Marmara Island marble and a number of broken tiles. Things are still going on with dating.

The Beylikduzu Municipality did underwater research along the 13-kilometer coast of the district. They found 8 artifacts, such as a breakwater, an ancient port, and sunken objects from the past. Researchers found important things about Istanbul's history, like a harbor that was 3.5 km long and a system of breakwaters.