The source of the Altmühl is close to the town of Ansbach. From here the river runs southeastwards as a narrow brook to enter the Altmühlsee (a lake) north of Gunzenhausen. After leaving Gunzenhausen the river describes a broad curve through the Franconian Jura. It enters the Naturpark Altmühltal (Altmühl Valley Nature Park), which is known for its natural environment: The meanders of the Altmühl river have cut deep gorges into the mountains of the Franconian Jura.