The city of Yazd is one of the oldest cities in Iran and the world. Owing to its unique historical, architectural, and cultural characteristics, it was inscribed on the UNESCO World Heritage List in 2017 under the title “The Historic City of Yazd.” The word Yazd literally means sacred and pure, and the name of the city refers to a holy land and the City of God.
In fact, Yazd is the world’s first living adobe city to be fully registered as a World Heritage site and represents an outstanding example of human adaptation to a desert environment. One of the most important features of this city is its distinctive adobe architecture and the extensive use of mud brick and clay, which are well suited to the hot and arid climate. The presence of qanats (A qanat or kariz is an aqueduct or channel dug underground so that water can flow through it to reach the surface) water reservoirs (Ab-anbars), and underground access corridors or a backwater (Payabs) has made sustainable life in the desert possible. The city’s windcatchers (Badgirs) are a brilliant example of natural ventilation in traditional architecture. Unlike many historic cities, the old fabric of Yazd is still inhabited. This historic texture includes old neighborhoods, narrow alleys, mosques, bazaars, historic houses, and water structures that together form an integrated and ancient urban structure.
The registration of Yazd on the UNESCO list not only confirms the city’s outstanding universal value, but also contributes to better preservation, the development of sustainable tourism, and the global introduction of Iranian and desert culture and architecture. The windcatchers of Yazd are among the most iconic symbols of traditional Iranian architecture and a remarkable example of human adaptation to the hot and dry desert climate. These ingenious structures functioned as natural cooling systems centuries before the invention of modern air-conditioning.
Windcatchers are essentially vertical structures built on the roofs of houses, water reservoirs, and public buildings. By directing airflow and creating pressure differences, they channel cool air into interior spaces and expel warm air. Windcatchers cool spaces in several ways.
Firstly, by guiding the wind that enters through upper openings and is directed into the building. Secondly, by creating air suction even when there is no wind; temperature differences cause air circulation and exit of warm air.
Thirdly, in many houses, the wind passes over the surface of water or the qanat’s underground channels, becoming cooler through evaporation. These windcatchers are made of mud brick, clay, and brick, and are carefully designed according to local wind directions. The most famous windcatcher in Yazd is that of Dolat Abad Garden, with a height of about 33 meters, which is the tallest adobe windcatcher in the world and one of Yazd’s most important tourist attractions.
Qanats have played a fundamental and multifaceted role in the province and historic city of Yazd. In an entirely arid and desert environment like this region, they have been essential for sustaining human life, the economy, and culture. Yazd is located in an area with extremely low rainfall and therefore lacks surface water or permanent rivers. Under such conditions, qanats made it possible to bring groundwater to the city using the natural slope of the land and make it suitable for drinking. This water was used for the daily needs of households and contributed to the survival and growth of the population.
Qanat water also played a vital role in agriculture and horticulture. The presence of qanats has had a significant influence on the culture and local identity of the people of Yazd and is considered a symbol of coexistence with the desert environment. The Zarch Qanat, one of the most important qanats of Yazd with a history of over3,000 years, once irrigated thousands of hectares of gardens and farmlands, including pomegranate, grape, almond, peach, and other orchards. Agriculture depended on this water, and the Zarch Qanat formed an important part of the local economy. The existence of qanats enabled the city of Yazd to emerge and grow in the heart of the desert; without a sustainable water source, urban life in this region would have been almost impossible. The network of qanats, combined with traditional elements such as water reservoirs and windcatchers, created a comprehensive system of water and climate management.
Water reservoirs (Ab,anbars) played a crucial role in the formation, continuity of life, and urban identity of Yazd, a desert city that has always faced water scarcity. They were the primary source for storing and distributing clean water to residents. Water supplied from qanats or seasonal rainfall was stored in reservoirs (Ab-anbars) so that it could be used throughout the year, especially during the extremely hot summers. Thanks to their special architectural features, including domes, windcatchers, deep reservoirs, and specific building materials, water remained cool, evaporation was minimized, and its quality was preserved. The water reservoirs of Yazd are a prominent example of traditional knowledge in water management, meeting the city’s vital needs without modern technology.