Its name was Çayağzı until 2005, when it was changed to Riva. It is told that it had around 500 households when Mehmed the Conqueror conquered it. Petrus Gyllius stayed in Istanbul between 1550-1551 and wrote a monograph about the Bosphorus. Gyllius states that the Greek villagers call the settlement “Rhebas,” and that the mouth of the river is suitable for ships to anchor. Following the conquest, Turks from the Black Sea settled in Riva.
The River Riva, springing near the Tepecik village in Gebze, passes through Pendik and Çekmeköy before entering Beykoz and is the main body of water that constitutes the Ömerli Dam Lake. As we know, this dam lake provides 48% of Istanbul’s tap water requirements. The river’s total length is 70 kilometers and 38 kilometers of it provide water. Following the Ömerli Dam Lake, the river passes through Koçullu, Ömerli, Sırapınar, Hüseyinli, Bozhane, Öğümce, Göllü and Paşamandıra to flow out to the sea at Çayağzı. The periphery of the rivers is covered in forests for %75-80 of its length.
The Small Kumköy Farm is in Riva. Its fertile soils were planted with corn, wheat and barley at the time. Nowadays, the summer hosts many visitors, especially in the summer. Its long coast, Eşek and Soğan islands nearby, its castle, lighthouse, tea gardens and cute restaurants make Riva into Istanbul’s summerhouse.