Yazd sits on the edge of the desert, between two ranges of hills and from these hills run a series of underground tunnels (qanats) that used to bring cool fresh water to the residents. Throughout the old city are covered stairwells that descend to cool rooms where water could be drawn. It is warm as we walk around and we are glad we've come south. We are told that the city is like an oven in the summer. The old part of the city is a maze of mudbrick buildings and alleyways, mercifully free of traffic, with courtyard houses with high walls and old wooden doors, mosques with blue-tiled domes, a covered bazaar, and peaking out above everything are the windtowers. These towers are designed to catch the breeze, and through a clever design, draw the air downwards to cool the building below. It helps explain how the city has existed in such harsh terrain for so many years -a man-made oasis. We are in Silk Road territory here - Marco Polo passed through on his travels and the bazaar still sells silk cloth.
One day we share a taxi with James and Pierre, another traveller, to visit Kharanaq. It's an old mud-brick village that has been all but abandoned for a new village of concrete breeze-block houses. The old adobe houses are ruined, but you can still wander down the covered alleys and climb up onto the roofs for a view of the countryside. An old caravanserai has been brilliantly restored but stands sadly empty and locked up except when tourists arrive. It would make an excellent hotel - as it was when it was a staging post on the route to Yazd.