Hohentwiel Castle

Hohentwiel is an extinct volcano in the Hegau region of Baden-Württemberg in southern Germany. The mountain is west of the city of Singen and 20 miles (30 km) from Lake Constance. Hohentwiel began forming, along with the chain of volcanoes in the Hegau region, about 7–8 million years ago, when a layer of volcanic ash and stone was laid down. The magma consists of phonolite. In the following millions of years, the core was opened 260 metres beneath the surface by the glaciers from the ice age. This formed the core that is now exposed, after the ensuing millions of years of erosion. Hohentwiel Castle, whose ruins are on top of Hohentwiel, was built in 914 using stone taken from the mountain by Burchard II, Duke of Swabia. Originally, the Monastery of St. Georg was within the fortress, but in 1005 it was moved to Stein am Rhein (now in Switzerland), and the Swabian dukes lost control of Hohentwiel. In the later Middle Ages the noble families von Singen-Twiel (12th–13th centuries), von Klingen (to 1300) and von Klingenberg (to 1521) resided here. In 1521, it was passed on to Duke Ulrich von Württemberg, who developed Hohentwiel into one of the strongest fortresses of his duchy. During this time, it began to be used as a prison, and in 1526, Hans Müller von Bulgenbach, a peasant commander, was imprisoned there before he was executed.The fortress resisted five Imperial sieges in the Thirty Years' War, under the command of Konrad Widerholt between 1634 and 1648. The effect was that Württemberg remained Protestant, while most of the surrounding areas returned to Catholicism in the Counterreformation. The castle served as a Württemberg prison in the 18th century and was destroyed in 1801 after being peacefully handed over to the French. Today the former fortress Hohentwiel is the biggest castle ruin in Germany. The modern-day city of Singen nestles at the foot of the mountain.

Staufen (Hegau) is a mountain of volcanic origin in Baden-Württemberg, Germany, near the town of Hilzingen.

Hegau-Gymnasium (German: Hegau-Gymnasium) is a gymnasium in Singen in the very south of Baden-Württemberg in southern Germany. The school is named after the extinct Hegau volcanic landscape.

Singen (Low Alemannic: Singe) is an industrial city in the very south of Baden-Württemberg in southern Germany and just north of the German-Swiss border.

Singen (Hohentwiel) station is an important regional railway junction and interchange station in the town of Singen in the south of the German state of Baden-Württemberg. Three railways now meet there, but in the past five railways connected to it. The station is served by InterCity trains on the Stuttgart–Zurich route.

Rosenegg is a hill in Baden-Württemberg, Germany, located 2 miles east of the town of Gottmadingen.

Hohenkrähen is a mountain in Baden-Württemberg, Germany.

Hilzingen is a town in the district of Konstanz in Baden-Württemberg in Germany.

Rielasingen-Worblingen is a municipality in the district of Konstanz, in Baden-Württemberg, Germany. It is situated on the border with Switzerland, 4 km south of Singen, and 20 km east of Schaffhausen. This town is twinned with the French town of Nogent-sur-Seine in the Aube department and the Italian city of Ardea. Rielasingen-Worblingen has five kindergartens, three elementary schools and two secondary schools.

Mägdeberg is a mountain in Baden-Württemberg, Germany.

Mühlhausen-Ehingen is a town in the district of Konstanz in Baden-Württemberg in Germany.

Gottmadingen is a municipality in the district of Konstanz, in Baden-Württemberg, Germany, situated on the Swiss border, 5 km southwest of Singen, and 12 km east of Schaffhausen. A first mention of Gottmadingen was in 965. Until the construction of the Singen - Schaffhausen railway line it was a tiny village. Economic growth began in the 20th century. Due to the high demand for workers in the new factories the number of inhabitants grew rapidly. Gottmadingen's industry was mainly based on the production of agricultural machinery. In the years 1960s and 1970s more than 4,000 workers were employed in the "Fahr" factory for agricultural engines. The factory was closed in 2003. Today's economy is based on several companies that settled on the former "Fahr" factory area. The municipal area of Gottmadingen comprises also the outlying villages of Bietingen, Ebringen and Randegg, as well as the hamlet Murbach. Both Bietingen and Gottmadingen itself have railway stations and benefit from rail connections to Schaffhausen and Singen. The village Randegg and the hamlet Murbach are served by buses from Switzerland with a connection to the Swiss villages Ramsen and Dörflingen as well as the city of Schaffhausen. The route also passes through the German exclave of Büsingen am Hochrhein and its outlying village Stemmer, crossing the international border four times.