A future Mars, one thousand years from now, which has collapsed back into a Medieval age was the backdrop for the 2015 short story anthology Medieval Mars. This story world idea imagined that Mars will be gifted with an even thicker atmosphere than Earth. That, coupled with Mars’ lower gravity, would make airships with relatively small gondolas possible, of the sort common in steampunk artwork. It also would make it possible for human beings to ride giant birds, especially in the places on Mars where the atmosphere is thickest. (And genetically engineered Komodo dragons also take flight within the pages of Medieval Mars.)
Human beings living on Mars as portrayed in Medieval Mars looked back at the past as time where technology became indistinguishable from magic. So the characters in these stories called the past "The Age of Magic" and revered swords made of titanium and other advanced metals from that time and the few bits of technology (like book readers) still remaining. "Lithium smiths" became the common term for those able to build batteries and electrical circuits, a term eventually applied to all experts in the technological past.
The story world also imagined that Spanish-language Baptists would spark a religious revival at some point prior to the main action of the stories, making a form of Protestant religion become steeped in nearly Medieval tradition. Making Spanish the language of prayer for most inhabitants of Mars.
Kristin Stieffel has crafted three novellas set within the backdrop of the world described above. Tales of the Phoenix contains all three novellas. The first of these, Flight, was itself featured within the pages of Medieval Mars. Its two sequel stories, Storm and Battle, haven’t been previously published anywhere.
Kristin’s Kingdom of Marineris is among the most technologically advanced societies on future Mars. Though even they really are only beginning to rebuild the world of scientific studies, the Age of Science.
These stories are rich in worldbuilding details, though even more focused on the memorable characters the stories portray.