Complex sentence: The Flåm Line runs from Myrdal, a station on the Bergen Line located in a mountain pass at above mean sea level (AMSL) to Flåm, located at AMSL.
Split into simpler sentences: The Flåm Line runs from Myrdal on the Bergen Line to Flåm. Myrdal is located in a mountain pass at above mean sea level (AMSL), while Flåm is located at AMSL.