900km across the Dasht-e-Lut desert in the east of Iran from Kerman to Mashad. Sand, camels, head wind and solitude.
The difficul depend very much on the current temperatures...
Overview
Season and temperatures
Ich cycled the route in june and the temperatures during daytime were 45°C! I would not recommend to do it later!
Water and Supplies
You will find water every day (see roadbook). If you happen to run out of water anyway, some iranian probably will have stopped already to offer you fruits and water...