下が見えてないだけまだいいだろ。
https://proxy.duckduckgo.com/iu/?u=http%3A%2F%2Fi.dailymail.co.uk%2Fi%2Fpix%2F2016%2F04%2F07%2F09%2F32EC43B100000578-3527843-image-a-25_1460019345747.jpg
https://www.dailymail.co.uk/news/peoplesdaily/article-3527843/Don-t-look-Chinese-tourists-struggle-walk-terrifying-glass-bottomed-passage-2-300-feet-high.html