A fall line commonly marks the border between a coastal plain and an upland area.
Others develop when river currents carry sediment into the ocean, which is deposited and builds up over time until it forms a coastal plain.
The two coastal plains meet at Kanyakumari, the southernmost tip of the Indian mainland.
They mostly consist of grassland and grassy woodlands on yellow and grey textured fertile soils.
[2] Another is the Swan Coastal Plain in Western Australia, which includes the city of Perth.