Dosch HDRI: Desert & Dawn is a valuable source of HDRI (High Dynamic Range Image) environments of outdoor spaces.

The 24 high-quality HDR images for desert and dawn backgrounds are provided in the most widely used formats:
Light-Probe (Angular Map)
Spherical Map (Latitude-Longitude)
Vertical-Cross

And each HDR image is provided in the industry standard .HDR. So they are useable in most rendering applications.