The most well known part of the Namib desert/Namib sand sea are its salt/clay pans such as Sossusvlei & Deadvlei.
However, from the park gates to Sossusvlei it is an approx. 70 km drive through the dunes (for 65 km on a tarred road). If you are at the gates by sunrise these orange dunes are a stunning sight.
Also the 'vleis' (especially Deadvlei) are magical with white salt/clay, black trees, orange dunes and a blue sky.
One of the most beautiful places we have visited...