Sanzao Island Japanese Invasion Ruins are a solemn reminder of when Japanese troops overran Sanzao in January 1938, massacred a thousand civilians that April, and slew thousands of migrant workers in May. Many residents were starved to death as the Japanese launched attacks on Guangzhou from there. The cemetery is the resting place of more than 10,000 war victims, while comfort women (sex slave) campsites are haunts of unspeakable crimes. Cliffside carvings listing Japanese who died at Sanzao Air Base, fortifications, and airport were left behind during the War of Resistance Against Japanese Aggression (1931-1945). The World War II ruins were named a cultural heritage protection unit of Guangdong Province in 1983.