u/Expert-Perception631

I have a friend visiting from the Midwest today for the next couple days. I asked him what he wanted to do/see for his trip and he said he wanted to see the subway above ground. While that is very doable I’m struggling to think of routes that look particularly interesting or beautiful for a tourist to see above ground. Today I’m meeting him at Penn station and we’ll be able to venture out more throughout the week. Does anyone have any suggestions?