The Blautal (Blau valley) and the Schmiechtal (Schmiech valley) are both parts of the former Danube valley. This valley was used by the Danube before and during the ice ages, when it carried even more water than today. As the modern Rhine did not exist then, the Danube also brought water from Switzerland, which goes down the rhine today. At the same time the limestone plateau of the Swabian Jura was lifted by the forces of the Alps orogeny, and subsequent the danube valley became deeper and deeper. The valley has several cut-off meander spurs, formed as meanders where the river finally has cut through the spur and thus created an shortcut.
During the Ice Ages, since 1.5 Million years BP, the Danube brought an increasing amout of detritus and started to partly fill in the valley it just created. The uplift of the Swabian Jura continued and during the Riß-Eiszeit (120.000 years BP) the Danube used a new bed a dozen Kilometers to the south. The Blau, Schmiech and Ach rivers today use a valley, which those tiny brooks never could have formed.
The spring of the Blau is called Blautopf, and has its own page. The river Ach is not the river Aach in the west of the Swabian Jura, which springs in the famous Aachtopf, although it is pronounced identical.
In many caves and shelters of the Blau valley, finds of the Stone Age were made. In the Alb-Donau-Kreis, the administrative area belonging to Ulm, archaeological excavations took place in 28 caves. In the area belonging to Ehingen 19 caves were excavated. One of the caves is developed as a show cave, the Hohle Fels (Hollow Rock). The age of the oldest finds from this cave was determined, using the C14-dating, to be 50,000 years. The time of the highest number of finds, which is assumed to be the time of the most intensive inhabitation, is the Old Stone Age about 15,000 bis 11,000 years BP.
The caves in Germany, unlike other stone age caves in Europe, have no cave paintings. The reason for this is quite mysterious and there is no simple answer. One of the theories is that there once were cave paintings, but they were destroyed by different climatic conditions than in for example France. The famous discoveries here were ivory artworks showing humans, animals, mysterious symbols and even some bone flutes. One of the most recent discoveries is a female figurine with enormous breasts and vagina, which obviously has some fertiliy bachground. Such figurines have been found in other parts of Europe too, and they are called Venus Figurines.
Every year on Labor Day (the 1st of May), the city of Blaubeuren organizes the Cave Hike Blaubeuren. The goal is to walk a trail of 10 km leading to the most important excavation sites (aka caves) between Blaubeuren and Schmiechen. This are caves like Hohler Fels, Brillenhöhle, Geißenklösterle and others.
Most of those caves are closed during the year, to protect the archaeological remains. But on this day the archaeologists are on site and make tours. Some of those archaeologist are quite famous, and it is always a unique event with the possibility to be guided by them and have the possibility to ask them questions.