Tourists visit the Jiuzhaigou Valley, a World Heritage site famous for its colorful pools and snowy mountains, in southwest China's Sichuan Province, Oct. 26, 2015. 

Tourists visit the Jiuzhaigou Valley, a World Heritage site famous for its colorful pools and snowy mountains, in southwest China's Sichuan Province, Oct. 26, 2015.  

Tourists pose for photos at the Jiuzhaigou Valley, a World Heritage site famous for its colorful pools and snowy mountains, in southwest China's Sichuan Province, Oct. 26, 2015.  

Tourists visit the Huanglong scenic spot, a World Heritage site famous for its colorful pools and snowy mountains, in southwest China's Sichuan Province, Oct. 25, 2015. 

Tourists visit the Huanglong scenic spot, a World Heritage site famous for its colorful pools and snowy mountains, in southwest China's Sichuan Province, Oct. 25, 2015. 

Tourists visit the Jiuzhaigou Valley, a World Heritage site famous for its colorful pools and snowy mountains, in southwest China's Sichuan Province, Oct. 26, 2015.  

Tourists visit the Jiuzhaigou Valley, a World Heritage site famous for its colorful pools and snowy mountains, in southwest China's Sichuan Province, Oct. 26, 2015. 

Tourists visit the Jiuzhaigou Valley, a World Heritage site famous for its colorful pools and snowy mountains, in southwest China's Sichuan Province, Oct. 26, 2015.  

Tourists visit the Jiuzhaigou Valley, a World Heritage site famous for its colorful pools and snowy mountains, in southwest China's Sichuan Province, Oct. 26, 2015.  

A tourist wearing Tibetan clothing poses for photos at the Jiuzhaigou Valley, a World Heritage site famous for its colorful pools and snowy mountains, in southwest China's Sichuan Province, Oct. 26, 2015.