Pelham Bay Park

In area, Pelham Bay Park in the Bronx is New York City's largest park, but in public consciousness it's much smaller. A big part of the reason is the paucity of public transportation. The park contains golf courses, Orchard Beach, and a historic mansion and grounds, but getting there without a car takes real planning.
The Bartow-Pell Mansion from the edge of the rear woods
Not having done any planning (except to check the Barlow-Pell Mansion website for its hours), we got in the car and crawled our way through construction traffic to the wet green corner of the Bronx called Pelham Bay Park, aiming first for the mansion. It's the only one remaining of the many large estate houses that used to dot this area; when the city acquired the land in the late 19th century, they all ended up going the way of the dinosaurs except this one, which, built around 1840, later became the headquarters of the International Garden Club, which added the formal gardens around the time of World War I. The mansion has been a museum since 1946, and it's been populated with period furnishings. There's some modest landscaping in the vicinity… …and a few trees that have a lot of personality… But things get wild pretty fast as you wander out back of the mansion grounds. A yellow-marked but partly overgrown trail (look out for poison ivy, and check for ticks when you're done) takes you along the shore of the Lagoon. On the other side of this water is a landfill on the far side of which sits Orchard Beach, but at this lower section, there's no civilization in sight.
With your back to the Lagoon you can look out over this lush sward. You can ride a horse in Pelham Bay Park, or bike on the bike paths. But the whole place has a very un-manicured quality; this park is huge, but it's about as different from Central or Prospect Park as you can get and still be a park. Of course, anytime there's a beautiful weekend day, people are going to take advantage. In this parking area by the ballfields (ballfields completely unused during our visit), people had gathered to, uh, sit in the parking lot and eat and socialize. One interesting sight and sound: men playing live percussion along with a recording of Latin music. Golf, beach, horses, a historic house, beautiful watery views – Pelham Bay Park has a lot. But it's not too conducive to just wandering about. Robert Moses, not Frederick Law Olmsted, shaped much of this area. In the mansion's little museum room, there's a photo of Fiorello LaGuardia using the Bartow-Pell mansion as a "City Hall in the Country" and a placard explaining that one reason the Mayor spent time here was to "keep an eye on" Moses's vast geographic manipulations.