A coastal plain is a flat, low-lying area of land adjacent to a sea coast. Coastal plains are often fertile and well-suited for agriculture. They are also home to many important natural resources, such as oil and gas.

Coastal plains can be formed in a number of ways, including:

• Deposition: Coastal plains can be formed by the deposition of sediments from rivers, streams, and glaciers.
• Erosion: Coastal plains can also be formed by the erosion of mountains and other high-relief areas.
• Subsidence: Coastal plains can also form when the land beneath them subsides, or sinks.

Coastal plains are important for a number of reasons, including:

• Agriculture: Coastal plains are often fertile and well-suited for agriculture.
• Natural resources: Coastal plains are also home to many important natural resources, such as oil and gas.
• Transportation: Coastal plains are often used for transportation, as they provide easy access to the sea.
• Recreation: Coastal plains are also popular for recreation, as they offer opportunities for swimming, fishing, and boating.