A hidden environmental crisis is unfolding in ancient caves near China’s Zhangjiajie Forest Park, famed for its massive quartz-sandstone pillar formations, which are said to have inspired the floating scenery that appears in the 2009 Hollywood blockbuster “Avatar.” Viral social media videos showing piles of trash in the area, some reportedly dumped over a decade ago, are prompting a mass cleanup of the karst caves. #CNN #News