The Manhattan skyline is breathtaking no matter where you see it from. The best locations however are from the Brooklyn Heights Promenade and from Long Island City. To get to Brooklyn Heights I suggest walking across Brooklyn Bridge from Manhattan and then exiting to your right. Turn around and head down Old Fulton St, turn left at Everit St and head up onto Columbia Heights until you see the promenade on your left. For LIC take the 7 subway 1 stop into Queens from Grand Central and get out at Vernon Boulevard. From there walk down to East RIver. I would also suggest taking the Roosevelt Island Tramway cable car as it has great views both ways on the Skyline.
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