If you want to do something totally free and absolutely amazing, take a walk across the Brooklyn Bridge. You walk on a special walkway above the traffic, which is speeding by underneath you, you have brilliant views of New York and it's all for free.
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When you do it be sure to take the subway to Brooklyn and walk back to Manhattan - that way you get a great view in front of you all the time. Also, before you start the walk, take the time to grab a coffee and go down to the park on the waterfront in Brooklyn and just sit down and take in the view - awesome. To walk from Brooklyn to Manhattan: Take the A train and get off at High Street. Then follow the signs, and the crowd, across Cadman Park to the Pathway. Once on the bridge, you'll have awesome views of Manhhattan.
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