Regensburg - the capital of Upper Palatinate in East Bavaria - is located at three rivers, the Danube, the Naab and the Regen. There are two islands in the city area called "Oberer Wöhrd" and "Unterer Wöhrd".
The name Regensburg is due to the term "Castra Regina" meaning "fortress by the river Regen" which was a Roman fortress in the 2nd century P.D. Therefore, the year 179 P.D. is regarded as the official foundation date of Regensburg, the official foundation document is an inscription in the East Gate of Regenburg that is still there.