Volcanic Scenery Around Hegau
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| In the Hegau |
Long-extinct volcanoes lie in the Hegau between Singen and Engen. They were formed around 14 million years ago and are to be seen today as an array of striking summits. On almost every summit there are historic castle ruins to explore. The most fascinating of these is on the Hohentwiel near Singen; covering more than 9 hectares, it is the largest ruined fortress in Germany.
Link: 
www.hegau.de/
