Bakırköy is a municipality and district in the European part of Istanbul Province, Turkey. Its area is 29 km2, and its population is 226,685 (2022). Bakırköy lies between the D.100 highway and the coast of the Sea of Marmara. Bakırköy has a large psychiatric hospital called "Bakırköy Ruh ve Sinir Hastalıkları Hastanesi", and is an important shopping and commercial center.

The Sea of Marmara, also known as the Sea of Marmora or the Marmara Sea, is a small inland sea located entirely within the borders of Turkey. It connects the Black Sea to the Aegean Sea via the Bosporus and Dardanelles straits, separating Turkey’s European and Asian sides. It has an area of 11,350 km2 (4,380 sq mi), and its dimensions are 280 km × 80 km. Its greatest depth is 1,370 m (4,490 ft).