Aarau is a town and municipality located in northern Switzerland. It serves as the capital of both the canton of Aargau and the district of Aarau. As the largest town within the canton, it is situated on the Swiss plateau in the valley of the Aare river, specifically on its right bank.
Geographically, the town lies at the southern foot of the Jura Mountains. It is positioned west of Zurich, 58 kilometres south of Basel, and 65 kilometres northeast of Bern, bordering the canton of Solothurn to the west. The municipality is German-speaking and predominantly Protestant.
In 2010, the area of Rohr was officially incorporated as a district of Aarau.