The Mayo Clinic is a highly respected group of clinics and hospitals located in Rochester, Minnesota, although it has satellite clinics in several locations throughout the United States. It is associated with the Mayo Medical School. Its origin can be traced to the founding of Saint Marys hospital, a 27 bed hospital, in 1889.
The Mayo is responsible for several innovative practices, the most important of which is the bane of Dr. House - the unified patient chart. In addition, it is almost unique among hospitals in that physicians working for it are paid a flat salary instead of being paid for how many patients they see or how many procedures they perform.
The clinic's website is one of the most authoritative and comprehensive medical sites for laymen on the internet.
Mayo Clinic Website