Sarıyer is a municipality and district of Istanbul Province, Turkey. Its area is 177 km2 and its population is 350,454 (2022). It is on the northeastern part of Istanbul's European side. Sarıyer also administers the Black Sea coast to the west of the mouth of the Bosphorus, including the neighbourhood of Kilyos. It borders Eyüpsultan to the northwest, Beşiktaş to the south and Kağıthane to the west. The mayor is Mustafa Oktay Aksu of the Republican People's Party (CHP).

Eyüpsultan or Eyüp is a municipality and district of Istanbul Province, Turkey. Its area is 228 km2, and its population is 422,913 (2022). The district extends from the Golden Horn all the way to the shore of the Black Sea. Eyüp is also the name of a prominent neighborhood and former village in the district, located at the confluence of the Kâğıthane and Alibey streams at the head of the Golden Horn. The Eyüp neighborhood is a historically important area, especially for Turkish Muslims, due to the presence of the tomb of Abu Ayyub al-Ansari, the prominent Medinan companion (Ansar) and standard-bearer of the Islamic prophet Muhammad.