Arkansas has a mix of mountains, valleys, thick forests, and fertile plains. On the western border is the Mississippi River. In the northwest is the Ozark Plateau and in the south is the Ouachita Mountains. The south and eastern parts of the nation are called the lowlands. Arkansas' highest point is Mount Magazine, at 2,753 feet high, in the Ouachita Mountains. The lowlands of Arkansas are made up of the Delta and Grand Prairie. Both these regions are very fertile agricultural lands. Arkansas is also home to many caves, such as the Blanchard Springs Caverns.