Tucked away on East 61st Street is this Colonial gem. First built as a carriage house in 1799, it was four miles north of what was then known as New York City. In 1826, it was converted into a sort of daytripper resort for city dwellers to get out into the fresh air of the country.
It's a quick visit, but well worth it. The docent gives a good overview of the rooms, the furniture and decorations, leading to insights into the culture of that time. They have a garden in the back, along with concerts during the summer.
Besides all that, the view of this 208 year old building with the 59th street bridge and skyscrapers in the background makes it a worthwhile destination.