Well-trod paths are wonderful, but every New York–loving endorphin addict should make it a point to tour the city’s startling industrial-residential present. This route is about seven miles: Start at the Delancey Street/Essex Street subway station, and head over the Williamsburg Bridge. Note what’s there (goth skateboarders, a save domino sign in alarming red, Hasidic families out for a stroll) and what isn’t (throngs of other runners, tourists). On the Brooklyn side, double back (left) on South 4th Street to Kent Avenue, then turn north (right) past defunct factories and rising condos, keeping the silhouette of Stuyvesant Town and the skyscrapers beyond to your left. Just after Kent becomes Franklin Street, turn east (right) on Greenpoint Avenue and run past churches, shoe-repair shops, and old-school diners. Head north (left) on McGuinness Boulevard and over the Pulaski Bridge (stay left). This becomes 11th Street, where you’ll pass the gigantic Five-Star Indian banquet hall, the Silvercup Studios placard, a pretty brick Steinway-piano warehouse, a strangely surreal parking lot for construction cranes; you’ll get a glimpse of the Chrysler Building. Turn east (right) at Queens Plaza North to the Queensboro Bridge footpath and pause for a look at the Upper East Side skyline. End on Second Avenue at 59th Street.