Group 70 is a non-profit educational organization of people from many countries all around the world and many walks of life seeking to make astronomy available to the peoples of the world. They began in 1988 with the goal of building a large amateur telescope, a 70 inches (1,800 mm) astronomical instrument. Upon completion it would be the largest telescope in the world built by and for amateur astronomers. Beyond building a large aperture telescope, they offer related instrumentation and services to those in amateur, professional and educational fields of astronomy.
As of mid-2008, the project has moved from San Jose, CA to Fremont CA and work has moved from the mirror to the steel and other optics.
Use of a comparable telescope in California is very expensive: a rental must be scheduled well in advance and the weather may not cooperate.