A memorial featuring a brothel where Japanese troops kept women as sex slaves during World War II opened to the public in Nanjing, East China's Jiangsu province on Dec 1, 2015. It is the first in China's mainland dedicated to the group, and was identified by victims as a military brothel run by the invading Japanese more than 70 years ago. The memorial in Nanjing covers more than 3,000 square meters and comprises eight two-story buildings. [Photo/China News Service]