Thirty books, some the kind you could pick up in your local library, others that are carefully hidden away from the general public for good reasons.
30 books to be found within a steampunk setting. Manuals, tomes, and blueprints galore!
A basin type hole in the middle of the plains. Once every so many years the rains come very hard and flood this place. Maybe that is where the tribes congregate for their tribal meetings.