The area around the headland is known as Twyni Bach ('small dunes') and this is new land. The 1902 map shows that the beach here is an extension of what was a small island. Today, this is where new or embryo dunes are formed.

Dunes start growing when dry sand is blown in by the wind and becomes trapped behind an object on the beach. This could be flotsam, pebbles or seawood. Ynyslas has pebbles brought north by longshore drift, forming a shingle ridge offering some shelter from the sea.

When the wind blows from the north west, sand from sand banks in the estuary is lifted and deposited in such traps. Stability is brought when some hardy plants begin to grow on the pile of sand and hold it in place. Thus we have embryo dunes.

Living plants grow sideways and upwards, binding the heap of sand and, each spring, they send out new shoots to collect more sand on top of the previous year's pile. The young dunes grow to meet each other and join up to form ridges at right angles to the direction of the prevailing wind.

Sea rocket and prickly saltwort have the thick fleshy leaves and tolerance of seawater for this initial phase. Then the old embryo dunes are colonised by the most important plant of the British dune sytems, marram grass.

Marram grass thrives on being buried now and again. When new sand blows over it, the plant simply grows upwards more quickly and branches out sideways for effective binding. Extremely deep roots are sent down. Can you imagine 12 metres? That's almost the height of three double deckers! This tall, spiky-leaved grass is one of nature's wonders.

The first dunes at Ynyslas are thought to date back to the fourteenth century. These older dunes can be seen behind the Visitor Centre.