The Black Rock Desert (The Playa) in Northwestern Nevada is considered to be one of the largest flat spots on the face of the Earth. The playa extends for approximately 100 miles (160km) northeast from the towns of Gerlach and Empire, between the Jackson Mountains to the east and the Calico Mountains to the west. The Black Rock Desert is separated into two arms by the Black Rock Range. It lies at an elevation of 3848 feet (1172 meters) and has an area of about 1,000 square miles (2,600 kmē). It is a perennial dry lakebed, meaning that it's dry most of the year. The wet winters will often cover the Playa with a temporary lake a couple of inches deep which helps to re-flatten the surface of the lakebed come summer time. This makes the Playa an ideal place for many activities such as setting land speed records, Land Sailing and of course launching rockets.
It is a magical place that you need to experience for yourself!
Images of the Playa
A few great sources of information on the Black Rock Desert and the dry lake bed we call "The Playa"