From cathedral steps, you can see the grand mansions of the Champagne houses - Veuve Clicquot, Tattinger, Ruinart, Pommery. Their chalk cellars run beneath Reims (3+ miles of Roman chalk mines). Kings didn't just get crowned here - they got crowned WITH Champagne. The houses put their prestige next to sacred ground on purpose. Exit cathedral, walk southeast toward Place Royale and Rue de Tambour (5-minute walk from cathedral). You'll see the ornate Renaissance mansions with wrought-iron gates. No need to enter (cellars cost β¬20-30) - just walk the exterior. The architecture itself tells the story: medieval spirituality + 17th-century capitalist wealth, side by side.
π BACKUP: Google Maps "Champagne Houses Reims" - they're all within 10-minute walk of cathedral.