6. the mountains and plains of the southern coast of the peninsula. The terrain is characterized by a long and narrow peninsula. Is bordered by the sea on both sides of the Gulf of Thailand and the eastern. Andaman Sea in the west The core of the peninsula consists of mountains and coastal plain that slopes down to the sea on both sides. The flat side An East Coast Over on the west coast Coast east coast is smooth and lift height. There are many beautiful beaches The coast West coast is sinking Make rugged coastline indented with a large number of small islands.