Inspiration for My Dungeons and Dragons Adventure 

Reminds me of a campaign I ran years ago. In a world where there were very very few dungeons and each was locked and hidden so that my players had to investigate towns and villages, paying vast amounts of coin to buy rumours and maps(most fake). Eventually they discovered that these dungeons, full of magical experimentations meshed with tinker gnome levels of devices throughout them, were created by a cabal of Technomancers. Near the end of the campaign the players discovered the technomancers called themselves the Vu'alt Teq and used the dungeons to research magic and technology combined with monsters and people. Fallout. I made magical Fallout. They hated me, but it was worth it.

I remember a sculpture of a jet at the playground by my grandparents house, when I was a small child. It was made of metal and got extremely hot in the summer sun. The children at the park, myself included, would climb on the jet and pretend to fly it. To cool it down we would dump buckets of water from a water spicket on the hot metal. I found the park recently. The jet is still there but is fenced off with signs to not climb on it. The pictures of the cowboy climbing fixtures you showed reminded me of the jet and other playgrounds with metal jungle gyms.

The aftermath of failed adventurers is a favorite source of writing inspiration of mine. Ussually narrated by a map, journal or other object. However, some of my best adventures are the plots of movies adapted to the genre. Ussual suspects, ground hog day/boss level, batman, joker, are all good. Seven deadly sins can also be adapted to adventure themes. Start at the end can be a fun twist on an adventure, in which the characters have all died and are resurrected to face an insurmountable evil. Battle of 5 armies is a good one off when all of your players cannot attend, give each them charge of organizing defense and fighting against one of the armies. Have fun with it.

We never know where inspiration comes from. Seeing others? Deffinetly one.