Governors Island is a real time commitment — fit it in only if it's a priority.
Allow Half day.
A short ferry drops you onto a car-free island of open lawns, historic forts, public art, hammocks, and a hilltop with 360-degree harbor and skyline views. Wonderfully relaxed and great for biking or a picnic — but it's seasonal (open roughly May–Oct) and there's little to do on a cold or rainy day.
Price
$5 round-trip ferry (free weekend mornings before 11am)