The Asklepion is an ancient medical center built in honour of Asklepios, the god of healing. It was also the world's first psychiatric hospital. The Asklepion gained in prominence under the Romans in the 2nd century AD, but a sacred site existed here as early as the 4th century BC. Many of the treatments employed at Pergamum, in complement with a sacred source of water that was later discovered as having radioactive properties, have been used for centuries and are once again finding modern application. These treatments included psychotherapy, massage, herbal remedies, mud and bathing treatments, the interpretation of dreams, and the drinking of water.