High Line, New York -- History

 * 1920's - dangerous tangle of rail, cars, pedestrians along 10th &11th avenues
 * 1929 West Side Improvement Project - massive reorganization of Manhattan's transportation infrastructure
 *  By 1960's trains had stopped running on High Line and southernmost section demolished 
 *  Steel structure began to deteriorate, depressing property values, shadows on street below as "incubator for unsavory activities"  
 *  Lack of consensus over who was responsible for dismantling it resulted in neglect that allowed nature to flourish above
 *  Elevated tracks became urban oasis for wildflowers, grasses, birds, trash
 *  Self-sown by birds and stowaway seeds carried by trains