With three kids under eight years old, New York City parents Kimberly and Sam Leopold made proximity to nature the top must-have during their recent apartment search. “We spend time in a park two or three times a day,” says Kimberly, who lives in a 750-square-foot South Harlem apartment with her husband and daughters. “Honestly, it’s a matter of survival. The kids are just happier when they can play and explore outdoors.”

And it turns out that a regular infusion of nature—in particular, seeing and being around trees—could help bolster kids’ thinking and reasoning skills, too. A recent British study of more than 3,500 city-dwelling children and teenagers from across London found that having a higher daily exposure to