Eisenherz

Smoke billows in dense clouds from towering brick stacks, painting the sky with saffron hues streaked with oily browns and yellows. The road leading to the factory is uneven and overgrown, flanked by crumbling brick buildings in various stages of decay.
Deeper: The factory is an industrial labyrinth, with gears and machinery of a bygone age, now forgotten. The iron gates, a colossal fabrication of beams, rivets, and bolts, bar entry to the graveled yard, and the corroded machines therein, their rust falling like dirty snow. The compound is surrounded by crumbling walls, once guarded by watchmen in decaying towers. Serrated ironwork atop the walls is a reminder that the factory once fiercely defended its secrets.
The Roots, the vast network of utility tunnels beneath, feed coal to forgotten machines deep underground. These colossal pumps, bellows, and boilers still power unknown mechanisms in distant locations across the Corrheic North. The doors to these tunnels are sealed by clockwork automatons, which have been functioning flawlessly since the days before the Fall.
Once a year, the factory's vault, Eisenherz, opens for a week, granting access to the underground labyrinth. Teams of engineers and opportunists rush to discover hidden treasures and lost knowledge among the ancient machinery. For the past three seasons, Floor Boss Arden Bowles has controlled access to the vault, running lotteries that favor the wealthy and well-connected. His corruption, known but tolerated, ensures a gold-heavy purse can secure a coveted spot in the first wave of explorers.