Springfield's health care community serves the area with more than 1,000 medical doctors practicing in all fields of specialization. The city's major hospitals are St. John's Regional Health Center, Cox Medical Center South/Cox Walnut Lawn, Cox Medical Center North, Lakeland Regional Hospital, and Doctors Hospital of Springfield. St. John's, the state's second-largest private health care facility, maintains centers specializing in the heart, cancer, sports medicine and rehabilitation, fitness, emergency trauma, and burn care. The many health care facilities located on South National Avenue have given rise to the nickname Medical Mile, where more than $200 million has been invested.