From the English-language website News Guangdong:
28 meters in height and 7 meters in diameter, Yanyuan (sic – should be Yangyuan) Stone resembles the male’s penis, enjoying a reputation of “the most marvelous stone in the world”.
Making sure that no one thinks Guangdong’s rocks are sexist, the Yangyuan Stone is not the only sexy rock around.
The Yinyuan Hole, on the opposite, resembles the female genital organ, and is 10.3 meters high, 4.8 meters in width and 4.3 meters long. The two stones are dubbed “Danxia miracles”.
See the stones on News Guangdong here and here, but don’t expect to be told where exactly these marvellous rocks are located.