The great cathedral boom of medieval Europe came to a sudden halt in the early 1300s. Builders literally downed their tools mid-project—and many cathedrals remain unfinished to this day. What happened? The Little Ice Age. A sharp climate shift brought famine, failed harvests, and soon after, the Black Plague, wiping out much of Europe’s population. The end of cathedral building wasn’t artistic choice—it was survival. | The Randall Carlson