Riva (also called Çayağzı) is a village in Beykoz intracity district of Istanbul Province, Turkey. It is a coastal village in the Anatolian part of Greater Istanbul, situated between Anadolu Feneri and Şile. Çayağzı creek flows to Black Sea with in the village and there is a wide beach to the west of the creek. The distance to Beykoz center is about 16 kilometres (9.9 mi). The population of Riva is 1,585 as of 2011. Before the First World War, majority of the village population was composed of Greeks. But after the population exchange between Greece and Turkey in the 1920s, Greeks left the village and Turks from the Black Sea region settled in the village.
Although a part of Greater Istanbul, the village still keeps some rural features. The Byzantine era Riva Castle sits on a hill where the Riva Stream (also known as the Rheba or Irve Stream) meets the Black Sea.
Beykoz (Turkish pronunciation: [ˈbejkoz]) is a district in Istanbul, Turkey at the northern end of the Bosphorus on the Anatolian side. Beykoz includes everything from the streams of Küçüksu and Göksu (just before Anadolu Hisarı) up to the opening of the Bosphorus into the Black Sea, and the villages in the hinterland as far as the river of Riva. This is one of the most pleasant and peaceful districts of Istanbul, with much greenery still intact. The mayor is Yücel Çelikbilek (AKP).
The mouth of the Bosphorus has always been a location to spark the imagination, and in ancient times was a place of sacrifice. Blood was spilt to petition Zeus and Poseidon for a safe journey across the treacherous Black Sea, without which no one would venture into those stormy waters.
The first historic people to settle the upper-Bosphorus were Thracians and Greeks and the ancient name for the area was Amikos (Αμικός in Greek) or Amnicus (Αμνικός), named after a Thracian king. However, the area has changed hands many times since. As well as being one of the most strategically important crossing points in history, the Bosphorus itself has always been rich in fish and opportunities for plundering the even richer communities around the Marmara, and Beykoz has been settled by wave on wave of invaders from around and beyond the Black Sea: Thracians, Bithynians, Persians, Greeks, Romans, Byzantines and finally Turks.
Beykoz 1908 SKD or commonly Beykoz 1908 is a sports club of Istanbul's historic Anatolian part district Beykoz, which was founded in 1908. Its colours are yellow and black. The club was founded as Mümeresat-i Bedenye Şubesi, and was renamed Beykoz Şark İdman Yurdu in 1911. In the year 1921 it merged with Beykoz Zindeler İdman Yurdu and took its current name. The club's football team returned to the TFF Second League after 17 years, at the end of the 2007 - 2008 season. The club's basketball team TTNet Beykoz competed in the Turkish Basketball League.