Answer the question from the given passage. Your answer should be directly extracted from the passage, and it should be a single entity, name, or number, not a sentence.

Passage: Between Bingen and Bonn, the Middle Rhine flows through the Rhine Gorge, a formation which was created by erosion. The rate of erosion equaled the uplift in the region, such that the river was left at about its original level while the surrounding lands raised. The gorge is quite deep and is the stretch of the river which is known for its many castles and vineyards. It is a UNESCO World Heritage Site (2002) and known as 'the Romantic Rhine', with more than 40 castles and fortresses from the Middle Ages and many quaint and lovely country villages. Question: What flows between Bingen and Bonn?
Middle Rhine
The question asks what flows between Bingen and Bonn.  The answer should be a single entity, not a sentence. "Middle Rhine" is the correct answer..