Although the Erg Chebbi, further east, is the more famous sand sea, the Erg Chigaga is actually the largest set of dunes in Morocco, both in terms of height (the highest are 300 metres high, nearly twice the height of the next highest in the country) and area (stretching for 40kms, compared to the 28kms of the Erg Chebbi). They are not as well know largely because they are harder to access, being 2 hours off-road drive from M’Hamid, which is already a long way from anywhere! This also means you have a fraction of the visitors who crowd the other sand seas and dunes, making the Erg Chigaga the only real destination for desert purists in Morocco.