Sand dunes

Sand Dunes are areas where the wind has blown sand into a ridge or hill.
In Europe they are usually next to a sea or lake. In the Sahara whole regions of Dunes are known as Ergs or Sand Seas.

Persistent wind action will eventually form the desert sand into chains of hills known as dunes.
Some dunes form at right angles to the wind direction and have a gentle slope up to the ridge with a steep drop on the far side. These dunes drift forward continuously.
Other dunes form into long rows in parallel to the wind direction and have long sharp ridges, and may have a steep slope on both sides.
Occasionally, the wind blows the rock or gravel surface completely clear of sand.

Dune du Pilat
- This is Europe’s biggest Sand dune on the Atlantic coast in southwest France, near the bassin D’Arcachon, at over 360 feet high (110 m).

Curonian Spit
- This is a 62 mile (98 km) Spit which forms a barrier separating the Curonian Lagoon from the Baltic Sea.
- It is located partly in Lithuania and partly in the Russian Kalinigrad Oblast.
- These are the highest moving sand dunes in Europe. Most of the Dunes are covered in pine forests.
- The average height is 98 – 115 feet (30-35 m), but some dunes reach 187 feet (60 m).
Vistula Spit
- The Vistula Spit is a narrow sandbank that separates the Vistula Lagoon from the Gdansk Bay of the Baltic. The highest Sand dunes reach 82 feet (25m) in height.

Sarykum Dune
- Sarykum Dune in Dagestan, Russian Federation. It is the largest sand dune in an area of sandunes on the northwest coast of the Caspian sea and is the highest sand dune in Eurasia.
- The Sarykum is very ancient and has a length of 1.9 miles (3km). whilst its height varies between 700-860 ft (213-262m) .

The Sahara
Great Sand Sea
- This is a large area of Sand dunes about 185 miles (300km) by 400 miles (650 km).
- It stretches from the Qattara Depression in western Egypt to eastern Libya.
Erg of Bilma
- This is a Sand Sea in the Fezzan located in Niger. The Fezzan is a geographical area in the Sahara covering southern Libya and northern Niger.

Empty Quarter
- This is the largest area of continuous sand desert in the world which occupies the southern third of the Arabian Peninsular.

Khongor Sand Dune
- Also known as the Khongoryn Els and the Singing Sands, it is one of the biggest Dunes in the world, located in the Gobi Desert in Northern China and Southwest Mongolia.
- It is 7 miles (12km) wide, 111 miles (180km) long, with a height of 262 feet (80m).

Dune du Pilat, near Bordeaux, France