About 23% of Taiwan's land area consists of fertile alluvial plains and basins watered by rivers running from the eastern mountains.

These plains mainly consist of flat rolling land, with scattered Buttes, canyons, and forests located in these areas.

The outer coastal plain consists of unconsolidated Tertiary deposits of sands, silt, and gravels.

This western plain consists of alluvial formation, with a general westerly slope owing to the deposit of silt from the mountain torrents in the sub-montane tract.

The coastal plain consists mainly of sand dunes and polders.

These plains consist of highly fertile alluvium, which made Wollongong so attractive to agriculturists in the 19th century.

Bangar plains are more upland, and consist of older alluvial soil.

The plain is not flat but consists of little drumlin hills.

Some smooth plains consist of infill in some medium sized craters.

Until the early nineties of the last century, the coastal plain of Antelias mostly consisted of open areas planted with orange and banana trees.