A 2,000-Year-Old Cooling System
Yakhchāls, meaning “ice pits” in Persian, were developed in ancient Iran over 2,000 years ago. These dome-shaped structures, built from heat-resistant mud bricks, were designed to store ice and food in the hot desert climate. Some were connected to qanats (underground canals) to enhance cooling.
How They Kept Ice Frozen in the Desert
The thick mud-brick walls of a yakhchāl provided insulation, while a specially designed windcatcher helped circulate cool air inside. In winter, water was frozen in shallow pools, then stored in the yakhchāl to last through the summer. Some structures could hold hundreds of tons of ice.
Used for More Than Just Ice Storage
Besides storing ice, yakhchāls were used to preserve food like dairy products, fruits, and even meat. Some cities relied on them to provide cold drinking water during scorching summers. The largest yakhchāls stood over 18 meters (60 feet) tall.
Still Standing Today
Many yakhchāls built centuries ago remain intact in Iran and Afghanistan. Though modern refrigeration has replaced them, these ancient cooling systems still function and attract engineers and historians studying their efficiency.
Over 2,000 years ago, Persians built yakhchāls—dome-shaped ice houses—to store and produce ice in desert climates. Made of heat-resistant materials, they used natural cooling methods to keep ice frozen. Some yakhchāls, built as early as 400 BCE, are still standing today.🧵👇 pic.twitter.com/TBX0qJPMrK
— Detective Tiger's Stories (@TigerDetective) February 12, 2025