Aalen (German pronunciation) is a former Free Imperial City located in the eastern part of the German state of Baden-Württemberg, about 70 kilometres (43 mi) east of Stuttgart and 48 kilometres (30 mi) north of Ulm. It is the seat of the Ostalbkreis district and is its largest town. It is also the largest town in the Ostwürttemberg region. Since 1956, Aalen has had the status of Große Kreisstadt (major district town). It is noted for its many half-timbered houses constructed from the 16th century through the 18th century. With an area of 146.63 km2, Aalen is ranked 7th in Baden-Württemberg and 2nd within the Government Region of Stuttgart, after Stuttgart. With a population of about 66,000, Aalen is the 15th most-populated settlement in Baden-Württemberg.