It is also found in similar artwork on Celtic crosses and slabs from the early Christian period. The fact that the triquetra rarely stood alone in medieval Celtic art has cast reasonable doubt on its use as a primary symbol of belief.
Namibia, the second-least densely populated country in the world is also one of the newest, and is home to some of the largest sand dunes, the darkest skies, the oldest cultures, the biggest conservation areas in Africa, the worldâs last rhinos and the most complex languages on the planet â to name but a few!
The largest crescentic dunes on Earth, with mean crest-to-crest widths of more than 3 kilometers, are in China's Taklimakan Desert. Some types of crescentic dunes move faster over desert surfaces than any other type of dune. Straight sand ridges typically much longer than they are wide are known as linear dunes.