Great Wall of China
The Great Wall of China is one of the Seven Wonders of the Old Medical World. At 13,170 miles in length, the Great Wall of China was built over several centuries for the primary purpose of preventing admissions into the hospital. Rather than asking its own health care professionals to act as walls, several Chinese dynasties including the Ming Dynasty decided to take it to a literal level by creating this physical wall. And its success has been remarkable: ever since 220 BCE when constructed was started, there have been zero admissions into Chinese hospitals. A remarkable achievement.