What is the name of the sea that connects the Black Sea to the Aegean Sea?

The Sea of Marmara is the sea that connects the Black Sea to the Aegean Sea. It forms the central link in the Turkish Straits system: the Bosporus connects it to the Black Sea, while the Dardanelles connects it to the Aegean Sea.

The Sea of Marmara lies entirely within Turkey and separates the country's European and Asian sides. Istanbul sits beside the Bosporus at its northeastern entrance, making the surrounding waterways one of the world's most important maritime passages. Ships travelling between the Black Sea and the Mediterranean commonly pass through this route.

In antiquity, the sea was called the Propontis, a name associated with sailing toward the Black Sea. Its modern name comes from Marmara Island, which was historically known for its marble. The sea covers about 11,350 square kilometres and reaches a maximum depth of roughly 1,370 metres.