What are you trying to say? Neither sentence quite makes sense as written. You might say "There's a nice way to get to know Amsterdam, by traveling along the river Amstel." Or "..., through travel on the river Amstel." But your sentences, as written, don't make it clear how the river allows you to get to know Amsterdam.
Well, I disagree, Sparky. If I was writing a tourist guide, I might well say "There's a nice way to get to know Amsterdam, along the River Amstel." The context would help - like the picture of the river trip boat. I wouldn't use 'through'. However, the main problem with the sentence is the word 'narrow'.