Bâdgir.

Yazd is also of foremost importance as a centre of Persian architecture.

To deal with the extremely hot summers, many old buildings in Yazd have magnificent windcatchers, and large underground areas.
A windcatcher (Persian: بادگیر‎ bâdgir: bâd "wind" + gir "catcher", Arabic: ملقف ‎malqaf [1][2]) is a traditional Persian architectural element to create natural ventilation in buildings.[3] Windcatchers come in various designs: uni-directional, bi-directional, and multi-directional. Windcatchers remain present in many countries and can be found in traditional Persian-influenced architecture throughout the Middle East, including in the small Arab states of the Persian Gulf (mostly Bahrain and Dubai[4]), Pakistan and Afghanistan.[5]