One of the fascinating things that you may not know about Hempstead, New York is that it was split in half due to Blue Laws, which seek to limit business activity on Sundays. Rather, it was the citizens' disagreement about the Blue Laws that caused North Hempstead to break away from modern-day Hempstead, which supported the Blue Laws.
Perhaps this support is why Hempstead is home to so many parks and green spaces where its residents, both canine and human, can relax. You'll find many people and pups enjoying Hempstead's parks each day.
Let Halls Pond Park be your first stop. You will love the calm and relaxing atmosphere that you will feel from the moment that you pull up. Walk Fido along the well-maintained trails that go around the pond. There are ducks to feed or, in your dog's case, bark at. Bring a book and blanket, because you will want to sit and stay a while. You will need a leash and a water bottle.
Next, you need to visit Hempstead State Park, which has over 700 acres of room to roam. Bring a leash, because you'll need it in some areas, but there are some leash-optional areas. Bring your camera, because this park is one of three and is known for its wildlife.