What Was a Kakelugn? The Scandinavian Farmer's 18-Hour Heater You've Never Heard Of

In the corner of a farmhouse outside Falköping in western Sweden, there is a column of white ceramic tiles reaching from floor to ceiling. Roughly two and a half meters tall, about eight feet, and almost a meter wide. No visible flame. No glowing coals. No smoke. But if you place your hand against the tiles, even hours after the fire inside has gone out, the surface is warm. The kind of warmth you feel from a stone that has been sitting in the sun all afternoon