Now, my world is old. Very old. And, unfortunately, the story locked me in a paradox. Namely, the colonization of the lush caves featured in another of my questions, which also have a name now (Harat Caverns). You see, a small group of intelligent dragons colonized this place 3.5 million years ago. They were in the renaissance age. How can I prevent them from progressing beyond the early industrial point? And, as a side note, why would they prefer medieval weaponry and customs? Do note that magic does exist.