The Met Cloisters
The Cloisters Museum and Gardens on NYC's Upper West Side are often referred to as "Manhattan's most serene museum." The Cloisters isn't merely a stop along the way, it is a destination. You will want to devote a chunk of your day to taking in all of the natural, medieval beauty this place has to offer.
The Met Cloisters, 99 Margaret Corbin Dr.
[Photo via @fausol]