Aksu is a neighborhood in Nallıhan District, in Ankara Province, Türkiye. Aksu lies at 1,265 m above sea level, in the Köroğlu mountains. It has 53 inhabitants. The nearest city is Beypazarı, 61 km to the east. Among the landmarks around are Dadastana (9.1 km) and Gökçekaya Dam (27 km).