- StumbleUpon. - StumbleUpon. Congratulations World Class Winners: New 7 Wonders of Nature. Another specific feature of Halong Bay is the abundance of lakes inside the limestone islands, for example, Dau Be island has six enclosed lakes.
All these island lakes occupy drowned dolines within fengcong karst. Photo #3 by Alex Stoen Panorama of Iguazu Waterfalls. Iguazu Falls, in Iguazu River, are one of the world’s largest waterfalls. They extend over 2,700 m (nearly 2 miles) in a semi-circular shape.