Cities with three rivers enjoy even more advantages than those cities located at the confluence of two rivers. Cities with three rivers tend to become more significant for this reason. A list of cities with three rivers would include Passau in Germany, Pittsburgh in Pennsylvania, and Three Forks in Montana. Some cases are ambiguous: the city of Koblenz is located at the intersection of the Rhine and the Moselle rivers (called the Rhein and Mosel, respectively), but the Lahn river joins the Rhine close to Koblenz, so that it might choose to consider itself a town with three rivers. Other such ambiguous cases exist, and in any case, proximity to more rivers in general is an advantage to a town - although the danger of flooding is thereby also increased.
The city of Tübingen also features three rivers. They contributed to the town's early successes. The three rivers which meet in Tübingen are the Ammer, the Steinlach, and the Neckar. Grammatically, each of these rivers has a gender: der Neckar, die Steinlach, and die Ammer. Linguistically, each of the names has an etymological history. The name 'Ammer' derives from a Celtic word amra meaning water or moisture. The Steinlach derives its name likewise from the geography of the region through which it flows: its channel is cut through layers of chalk, revealing at times fossils. The Neckar's name is derived from a likewise Celtic word, nik or nikros, meaning "attacking" or "raging" waters.
The Ammer begins northwest of Tübingen near the town of Herrenberg. Its general course is southeasterly, approaching the Neckar, with a few minor deviations. In 1493, a canal was created, drawing from the Ammer. This canal begins near the town of Unterjesingen, west of Tübingen. The canal runs roughly parallel to the Ammer, south of it. While the Ammer runs tangent to the northern boundary of Tübigen's old town area, the canal runs directly into it. The old town area is thus bounded by the Neckar on the south and the Ammer on the north. The old town itself is thus situated on shallow ridge, sloping down to south and to the north. The Ammer canal, then, lies north of the high point of the old town. In the northeastern quadrant of the old town, the Ammer canal splits, one branch returning to the Ammer, and the other branch running through a deeply cut underground channel to the Neckar. The Ammer continues, veering sharply northeast away from the Neckar for a short detour around the small mountain, or big hill, known as the Österberg. It curves southeasterly again, and enters the Neckar.
The Steinlach begins almost directly south of Tübigen, near the village of Talheim. Talheim is slightly southeast of Mössingen. From Talheim, the Steinlach meanders naturally for a few kilometers, but then becomes perfectly straight in segments. In 1861, civil engineers straightened the river. Straightening a river changes its flooding patterns, increases the drop to be harnessed by mills, makes it more predictably accessible for irrigation, and allows for easier navigation. In the case of the Steinlach, flooding patterns and mill usage may have been behind the impetus to straighten the river. Trees, now quite tall, were systematically planted along both sides of the river, and walkways constructed, created a park-like setting for several kilometers.
The Neckar is by far the largest of Tübingen's three rivers. Tübingen is merely one of many towns and cities along the course of the Neckar. Near Tübingen, the Neckar has been straightened. Most of the civil engineering to straighten the Neckar - such work is called Begradigung or Korrektion - was done to manage flooding and to create smooth and level patches of ground near the river on which factories could be build. Much of this was done in the early 1800's. Another such project was performed in 1911. The later project also created the Neckarinsel, a long thin island in the river which lies directly south of the old town. The island is approximately 500 meters long, and known for a statue honoring the author Friedrich Silcher, and for the Platanenallee, a park-like planting of two parallel rows of trees with a pathway between them. These two rows of trees were already in place before the island was created, and were originally somewhat longer than they are today. The Neckar plays an important role in the Tübingen's life. Its scenic quality makes it part of the town's allure to tourists, and university students conduct an annual race of Stocherkahn boats - shallow, gondola-like boats which are poled, not rowed. The Neckar enters Tübingen from the southwest and leaves heading northeast, and is tangent to the southern boundary of the old town.
The landscape along the Neckar and the Ammer includes a great deal of grape-farming on the hillsides. Wine from these valleys has a centuries-old tradition. The Steinlach valley is less frequently a site for vineyards. A general knowledge of the geography of these three rivers is a valuable aid to hikers exploring the region by foot.
