Two visitors take pictures at the Ping Chau Island in south China's Hong Kong, May 12, 2013. Ping Chau, also named Tung Ping Chau, lies in the northeast corner of Hong Kong and is part of the Hong Kong Geopark. The island is home to shale rocks in various shapes which makes it a popular tourist attraction. (Xinhua/Chen Xiaowei) 

Visitors tour at the Ping Chau Island in south China's Hong Kong, May 12, 2013. Ping Chau, also named Tung Ping Chau, lies in the northeast corner of Hong Kong and is part of the Hong Kong Geopark. The island is home to shale rocks in various shapes which makes it a popular tourist attraction. (Xinhua/Chen Xiaowei) 

Two visitors take pictures at the Ping Chau Island in south China's Hong Kong, May 12, 2013. Ping Chau, also named Tung Ping Chau, lies in the northeast corner of Hong Kong and is part of the Hong Kong Geopark. The island is home to shale rocks in various shapes which makes it a popular tourist attraction. (Xinhua/Chen Xiaowei)

 A visitor is seen at the Ping Chau Island in south China's Hong Kong, May 12, 2013. Ping Chau, also named Tung Ping Chau, lies in the northeast corner of Hong Kong and is part of the Hong Kong Geopark. The island is home to shale rocks in various shapes which makes it a popular tourist attraction. (Xinhua/Chen Xiaowei) 

Visitors tour at the Ping Chau Island in south China's Hong Kong, May 12, 2013. Ping Chau, also named Tung Ping Chau, lies in the northeast corner of Hong Kong and is part of the Hong Kong Geopark. The island is home to shale rocks in various shapes which makes it a popular tourist attraction. (Xinhua/Chen Xiaowei)