The anchor of the Gowanus neigh­bor­hood is this famous­ly pol­lut­ed canal. The Car­roll Street Bridge is the old­est retractable bridge in the US (and one of only four left). Recent­ly, the canal and sur­round­ing build­ings has been con­sid­ered for list­ing on the Nation­al Reg­is­ter of His­toric Places.