Giengen is a former Free Imperial City located in the state of Baden-Württemberg in southern Germany. It is situated in the district of Heidenheim at the eastern edge of the Swabian Alb, positioned near the border with Bavaria.
The town is situated on the Brenz River, approximately 30 kilometers northeast of Ulm. Historically significant as a Free Imperial City, it remains a notable geographical point within the region's river landscape.