Vietnam's embarrassment of geological riches varies as you go from north to south. Up north, the karst (limestone) geology creates natural wonders like Ha Long Bay and Hanoi's many lakes. In Central Vietnam, near the town of Mui Ne, sand dunes in red and white hues attract curious travelers.
In the south, the Mekong Delta allows visitors to look at an ancient riverside lifestyle and a habitat that provides plenty of fodder for biologists — the Delta has yielded about 10,000 new species since scientists started to study the area.
