Though many city dwellers may not realize it, there are numerous nature trails in NYC, perfect for outdoor activities and escaping the city's busyness.
The website My Inwood has some great then & now pictures of this northern neighborhood on Manhattan, which remained very rural into the early 20th century.
Manhattan is a bigger island than people think. Photographs from a hike in Fort Tryon Park and Inwood Park, which are just around the corner from each other.