One of the first places we visited in Yazd, after taking the night train from Tehran, was the Dowlat-Abad Garden. Well, 'garden' is perhaps a bit misleading, as the grounds are fertile fields with fruit trees. In the middle section there is a long rectangular shallow pond with high fir trees and small orange trees lined up on both sides.
But the green and lush environment is quite a contrast compared to the rest of Yazd, one of the largest cities built almost entirely out of adobe. The city is an important centre of Persian architecture. Because of its climate, it has one of the largest networks of qanāts, underground canals, in the world, and Yazdi qanāt makers are considered the most skilled in Iran.
Some of the qanāts surrounding Yazd, transport water over tens of kilometres from the nearby snow capped mountains. Our guide, Mohammed, whom we first met this morning, explained to us that the work was so dangerous that the crew digging these underground canals were wearing the traditional clothes one would wear when being buried after passing away.
To deal with the scorching summers, the average high in July in Yazd is 40°C, many old buildings in Yazd have great wind towers and large underground areas. The Dowlat-Abad Garden has the biggest wind catcher in Iran, 33 meters high. It is rebuilt after the original bâdgir collapsed in the 1960s, I believe by an earthquake. But anyway, all adobe structures are 'new' as workers regularly maintain the structure as otherwise, they will return to dust.
When the qanāts are used in used in conjunction with a wind tower, they provide extra cooling. The chimney-like structure typically positioned above the house has various openings at the top, and one of its openings, the one opposite the wind direction is opened to move air out of the building.
Incoming air is pulled from a qanat below the house. The air flow across the vertical shaft opening creates a lower pressure and draws cool air up from the qanat tunnel, mixing with it. The air from the qanat is drawn into the tunnel at some distance away and is cooled both by contact with the cool tunnel walls and water and by the transfer of latent heat of evaporation as water evaporates into the air stream.
In dry desert climates, this can easily result in a 15 °C reduction in the air temperature coming from the qanat; the mixed air still feels dry, so the basement is cool and only comfortably moist. Wind tower and qanat cooling have been used in desert climates for over 1000 years.
And, of course, as with all the older structures, the decoration of the structure is amazing. The insane geometric ceiling patterns, detailed woodwork and colourful glass make this a pleasant location for a half days visit.
I could not find the official website, but I am sure all hotels in Yazd can help you to arrange transport to the garden. Should you be in need for a guide in Yazd, then please contact me, I am still in contact with Mohammed and can bring you in contact with him. He is fluent in English and is a wonderful person to hang out with.