The large-scale state psychiatric hospitals, referred to as "asylums," were built in the USA in the 19th century and generally have a bad reputation in Japan as institutions with an unpleasant environment for the patients. Asylums were not built for institutionalizing mental patients. The original meaning of the word asylum is a "retreat" or "sanctuary," and these institutions were originally built to act as sanctuaries for the protection of mental patients. The field of psychiatric medicine in western countries in the 19th century began to embrace the concept of "moral treatment" for mental patients, including no restraint of the patients and treating them in a more open environment. With this background, asylums were built according to the efforts of social activist Dorothea Dix with financial assistance from the Quakers. The psychiatrist Dr. Thomas Kirkbride had a large influence on asylum architecture, and believed that the hospital building and environment as well as location have healing effects on the patients, which he called the "therapeutic landscape". Kirkbridelater proposed an architectural plan that became the basis for subsequent mental hospital architecture, and many asylums were built according to this plan. As the architecture was considered part of the treatment, many leading architects and landscape architects at the time became involved in building asylums. In the later half of the 19th century, over 150 asylums were built across the USA. However, moral treatment fell out of favor toward the end of the 19th century, and the concept of therapeutic landscape was also neglected. The hospitals had many uncured patients, and caregivers became pessimistic about the efficacy of the treatments. Abuse and neglect of the patients were also common. The environment at the asylums deteriorated, which created the image of asylums that, we hold today. Many asylums have been demolished or abandoned. These early attempts at asylum failed due to insufficient treatment methods. However, the concept of the therapeutic landscape that comprehensively sees the architecture of the hospital building and landscape of the property as part of the treatment as well as the architectural beauty of asylum buildings may deserve reevaluation.