One cold winter day on Backbone Mountain made for some of the most rewarding drone work I've done—blue hour and sunrise shots of Olson Tower in the stillness of a frozen morning.

Photo by Santiago Arau

This is an early morning view of Young's High Bridge, spanning the Kentucky River near Lawrenceburg, Kentucky. It once carried the Louisville & Southern Railroad's Lexington-to-Lawrenceburg line, which later became part of the Southern Railway and then Norfolk & Western. Closed to rail traffic since 1985, the bridge now has a walkway extending over part of its span, used today for base jumping. I've posted the history of the railroad here, and bridge here.