https://www.findinphilly.com/philadelphia-activities-list/ziplines-aerial-parks
Ziplines & Aerial Parks | Find In Philly
aerial parksziplinesfindphilly
https://wvstateparks.com/parks/audra-state-park/park-history/audra-state-park-aerial-1440x960-3c4e112f-1407-4b17-9af4-a7f4544a4210/
Audra-State-Park-aerial-1440x960-3c4e112f-1407-4b17-9af4-a7f4544a4210 - West Virginia State Parks
https://reuther.wayne.edu/node/6519
Walter P. Reuther Library (9710) Parks, Aerial View, Belle Isle, Detroit, 1942