Summer is here in the Northern Hemisphere, and a lot of people are looking to keep themselves and some of their foods and drinks cool.

There are fans, there’s A/C, there’s refrigerators and freezers.

Or, if you want to go old school, you could try a yakhchāl, a storage building which could keep foods cold all year long.

And they were used over 2,000 years ago.

In some ways the yakhchāl is accomplishing the same goal as a modern refrigerator.

Today, the back of the fridge sends a refrigerant through those coils on the back.

It changes back and forth between liquid and gas forms, and as it does, it draws heat away from the inside of the fridge and sends that heat out into the external air.

A yakhchāl also draws heat away from its contents, largely through the shape of the building.

The clue is in the name: in Persian, yakhchāl means “ice pit.”

Inside the structure is a deep pit.

The building is sort of cone shaped, which guides heat upward toward vents.

The walls are made of a thick, heat-resistant material, too.

At the bottom are vents that can let in cool air; and often yakhchāls were built near underground aqueducts.

Ice could form there in the winter and would stay cold even in summer.

Yakhchāls were in use at least as early as 400 BC, which is near the time that a dessert called faloodeh became popular in the region.

It’s a bit like a sorbet with rice noodles.

If all of this complex and ingenious ancient refrigeration work was part of an effort to make sure there were sweet treats around in summer, I can’t say I’d be surprised.

Yesterday we told you about Carhenge, in Nebraska.

Today we head to Munfordville, Kentucky.

The town’s onetime mayor, Chester Fryer, loved rocks.

So in his rock garden, he decided to make his own Stonehenge.

He says shadows shine through the stones during the summer and winter solstices, just like the original.

Yakhchāls, Āb Anbārs, & Wind Catchers — Passive Cooling & Refrigeration Technologies Of Greater Iran (Persia) (Cleantechnica)

Kentucky’s Stonehenge is one man’s rocky wonderland (FOX Lexington)

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