Orbe (river)

The Orbe (French: L'Orbe) is a river of the Rhine basin. It starts in France and flows to Switzerland to finally flow into the river Aare. On the final leg of its course, it takes the name La Thièle or La Thielle. Not to be mistaken with the Orbe, which is a tributary of the Arrats.

The Orbe has its source near Rousses, forms the lac des Rousses before flowing down to lac de Joux in Canton of Vaud, Switzerland. It disappears naturally underground for a stretch of 4 km, to reappear in Vallorbe - where a special ecotourism site was created, the Vallorbe Caves (note, to re-edit - http://www.grottesdevallorbe.ch/). Soon after, in Orbe, the river merges with the Talent and takes the name of Thielle. Flowing through Yverdon-les-Bains, it joins the lac de Neuchâtel. It flows out of it through the Thielle channel to the Nidau-Büren channel in Nidau, just before the regulating dam Port established between Port and Brügg that controls the levels of the three lakes of Seeland.

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Wikipedia