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!
This type of sand dune requires a large amount of sand and strong winds. The fourth and largest type of sand dune is the longitudinal dune. Longitudinal dunes are large symmetrical ridges of sand that form parallel to the primary wind direction. These dunes are straight and regularly spaced, with barren ground in between each dune.