Aksu is a village in Devrek District, in Zonguldak Province, Türkiye. Aksu lies at 672 m above sea level, in the Akçakoca Dağları mountains. It has 543 inhabitants. The nearest city is Devrek, 24 km to the northeast. Among the landmarks around are Heraclea Pontica (38 km) and Köprübaşı Dam (14.9 km). Among the natural features are Gümeli Porsuğu (11.4 km).