Thailand floods monitored by a NASA satellite. Original from NASA. Digitally enhanced by rawpixel. Free Image from public domain license 
Infrared-camera view of the New River Gorge Bridge in Fayette County, West Virginia. Original image from Carol M.… Free Image from public domain license 
Fontana Dam, North Carolina, Appalachian Trail. Original image from Carol M. Highsmith’s America, Library of Congress… Free Image from public domain license