You can do a lot more with mud than one might think. Today we visited a five storey fortress built entirely out of mud. It had apparently stood there for hundreds of years, but I still felt a little nervous standing on the fifth floor knowing that the only thing supporting me was mud.
Another interesting sight was a "pigeon tower". The locals created towers for pigeons to live in, with the aim of collecting their excrement to use as fertiliser. They tried to make the towers as appealing as possible for the wild pigeons. They included over a thousand little nesting sites, and made sure that the tower was impregnable to cats and lizards.
Similarly ingenious was the "ice house". This huge building was filled with ice in the winter and then used to cool things in the summer. The Walls were made of mud three metres thick, the base of the building was deep underground, and holes allowed melted water to flow away. All this allowed the ice to last well into summer.
The highlight of the day was Chak Chak, an important Zoroastrian pilgrimage site. During the Arab conquest, a Zoroastrian princess reportedly fled into the mountains and, lacking water, threw her staff into a rock, causing water to pour out. The water spring is now a Zoroastrian temple, however the highlight is more the views of the spectacular desert mountains than the temple itself. The holiness of the spring was somewhat spoiled by the use of a plastic bucket to catch the seeping water.
Tomorrow I'll be taking a bus to Shiraz.