A couple years ago we did a four day trip down the Romantic Road and stopped in Nördlingen. It is one of the most attractive towns in the central part of the Romantic Road.
The town of Nördlingen is a large district town in the Swabian district of Donau-Ries in Bavaria. The former imperial city is the largest city in the district, and it shares with its neighbors to the north (Rothenburg and Dinkelsbühl) the distinction of being one of the only remaining walled medieval towns in Germany. Nördlingen, however, is far less crowded than the other two, and offers an additional attraction of geological interest.
Nördlingen lies in the Nördlinger Ries, which had the impact crater. The depression is interpreted as a meteorite impact crater formed about 15 million years ago. Through the scientific research of the Ries event in Nördlingen became known worldwide. The crater is most commonly referred to simply as Ries crater or the Ries. The original crater rim had an estimated diameter of 24 kilometers (15 mi). The present floor of the depression is about 100 to 150 m (330 to 490 ft) below the eroded remains of the rim. The Ries is traversed by the Wörnitz and the Eger river; the former flows 30 kilometers southeast into the Danube.
It first it was assumed the Ries was of volcanic origin. Eugene Shoemaker and Edward C. T. Chao showed in 1960 that the depression was caused by meteorite impact. The key evidence was the presence of coesite, which, in un-metamorphosed rocks, that can only be formed by the shock pressures associated with meteorite impact.
Shoemaker was encouraged and then convinced by the Nördlingen St. George’s church, that was built of locally derived suevite. The suevite was formed from mesozoic sediments shocked by the bolide impact.