In addition to generous interior landscaping, CV has parks on 2 sides:
Cadman Plaza Park 1 block from Concord village, with a farmer's market 3 days per week.
Walt Whitman Park Across the street from Concord Village, adjacent to Cadman Plaza park. 
McLaughlin Park Across the street from Concord Village, with play equipment and basketball courts

And it's only 15 minutes to Brooklyn Bridge Park An 85-acre waterfront park with activity spaces, a carousel, food, and more, and to Hillside Dog Park, one of the largest dog parks in NYC.

Other attractions in walking distance include
BAM A performing arts venue in Brooklyn. It has been open since 1861, serves over 500,000 people annually, and is known as a leader in contemporary performing arts.
Borough Hall Greenmarket A year-round greenmarket open 3 days a week.
New York Transit Museum A kid-friendly museum about public transit.
Brooklyn Historical Society A 150-year old museum and library dedicated to this history of Brooklyn.
Dumbo Heights A recently renovated business complex.
MetroTech An educational, business, and cultural complex.