The ancient 'city' mystery at the bottom of the lake no one knows for thousands of years
Phu Tien Lake is the third largest in Yunnan Province (China), behind Dien Tri Lake and Nhi Hai Lake. But in three lakes, it is the deepest lake, with places up to 155m.Top natural wonders you may never know
From rivers flowing through deep pools in Europe to rainbow waterfalls and chocolate hills, the natural wonders below are still very unknown.