Attraction · Treuchtlingen · Updated on 1 November 2026.
Fossa Carolina is an attraction in Treuchtlingen, Bavaria. This place has a story in the app. Within 340 m you'll find a bench and a public toilet.
Story · Fossa Carolina
You're standing at the Fossa Carolina, in Graben, a part of Treuchtlingen. Look at the water in front of you. It could pass for an ordinary pond or ditch, but it's a piece of a canal more than twelve hundred years old. In German it's called the Karlsgraben, after Charlemagne.
Read the whole story in the Outdoor Pitstop app: check in at this place and it is yours (with Pro; new users are Pro for the first 4 weeks).
10 photos from Wikimedia Commons. In the app you add your own photo when you are there.
The Fossa Carolina is part of a very old canal in Beieren. Charlemagne had it dug in 793, because he wanted to connect 2 river systems: the water flowing towards the Rijn and the water flowing towards the Donau. At this spot, the 2 systems are only about 2 kilometres apart. The work got stuck in boggy ground, and so far researchers are not certain whether the canal was ever fully finished. You can find the Fossa Carolina in Treuchtlingen, in the Graben district.
The water in front of you looks like an ordinary pond or ditch, but it is a section of the old canal. About 500 metres of it is still under water. Along the banks you can see earthen embankments, some of which rise as high as 10 metres. The embankments continue for about 1.2 kilometres in total. If you walk a short way north, you will find a dry section of the canal bed, about 700 metres long. Here the embankments have almost sunk away. Look carefully at the landscape and you can still follow the line of the canal.
Karel de Grote ordered the work at a difficult time. He had put down an uprising by the Saksen, and the land was suffering from famine. Even so, he sent many workers to Graben and personally supervised the project for weeks. Einhard, writing some 20 years later, described endless rain: whatever was dug out during the day had filled back in overnight. Geologists now know why. Beneath the clay lies a layer that behaves like quicksand. At the end of 793, the work stopped. Other sources say the canal was in fact completed, perhaps with ponds, dykes and dams. The plan later inspired the ruler of Beieren, whose Ludwigkanaal opened in 1846.
Fossa Carolina has a bench 250 metres away, close to Naturpark Altmühltal, and there is one more bench within 500 metres. The nearest public toilet is 344 metres away, on Karlsgrabenstraße, and it is free to use. Within 500 metres there is one public toilet in total. There is no drinking water point near Fossa Carolina according to our map, with none within 1 kilometre, so it is worth bringing your own water.
The nearest pitstop of each kind within 1 km, as the crow flies. No water point, bike pump or honesty box within 1 km.
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The Fossa Carolina is a canal in Graben, part of Treuchtlingen, that is over 1,200 years old. It is also called the Karlsgraben.
The canal was ordered to be built in 793. The work was halted shortly before the end of that year.
The canal was meant to connect the Schwäbische Rezat and the Altmühl, linking two river basins. Only about 2 kilometres of flat land lies between them, at the European watershed.
The earthen embankments together measure about 1.2 kilometres in length. Around 500 metres of the canal is still under water.
Yes, the nearest bench is 250 metres from the Fossa Carolina, at Naturpark Altmühltal. There is 1 bench within 500 metres.
Yes, the nearest public toilet is 344 metres away, on Karlsgrabenstraße, and it is free to use. There is 1 public toilet within 500 metres.
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