The NY State DEC forced the local towns, including NYC to close all its landfills 30-40 years ago due to seepage from toxic chemicals into the ground water. Thus a half dozen or more were covered and capped. One in L.I. became an accessible park with hiking trails, but not for bikes. The two in Brooklyn, now called Shirley Chisholm State Park, got covered and has gravel trails installed where you can bike. It’s a very nice 10-12 mile gravel ride with great views.