When you see the people in The Eastern Caverns, you will see that there are some women wearing a tight red dress that's called cheongsam, which is a Chinese traditional clothes. However, the truth is, Cheongsam was actually originated from the Manchu, who are not Chinese. 400 years ago, the Manchu people, conquered China and their cultures blended in with the Chinese culture. They introduced some clothes, including the cheongsam, which eventually blended in the Chinese culture.
Let's assume that nobody ever found the opening behind the waterfall and arrived at the Eastern Caverns, there will be no cheongsam, just outfits similar to kimonos, like in the past 2000 years ago in China.