The most outstanding are the Kwahu (Mampong) Scarp ( Kwahu Plateau) in the south and the Gambaga Scarp in the north.
The southwestern, northwestern, and extreme northern parts of the country consist of a dissected peneplain (a land surface worn down by erosion to a nearly flat plain, later uplifted and again cut by erosion into hills and valleys or into flat uplands separated by valleys); it is made of Precambrian rocks (about 540 million to 4 billion years old).
They occupy a large area called the Lake Volta, an artificial lake that extends far into the central part of the country behind the Akosombo Dam and covers about 3,275 square miles (8,500 square km).
Along the north and south, and to some extent along the west, the uplifted edges of the basin give rise to narrow plateaus between 1,000 and 2,000 feet (300 and 600 metres) high, bordered by impressive scarps.
The country takes it name from the great medieval trading empire that was located northwest of the modern-day state until its demise in the 13th century.
Direct sea trade with Europe, established in the 15th century, had much impact on the area’s inhabitants, many of whom actively traded with the Portuguese, Dutch, British, and other Europeans.
Although relatively small in area and population, Ghana is one of the leading countries of Africa, partly because of its considerable natural wealth and partly because it was the first black African country south of the Sahara to achieve independence from colonial rule.
In addition to being known for its lush forests, diverse animal life, and miles of sandy beaches along a picturesque coast, Ghana is also celebrated for its rich history—its habitation possibly dating from 10,000 —and as a fascinating repository of cultural heritage.
Most of the remainder of the country consists of Paleozoic deposits (about 250 to 540 million years old), which are thought to rest on older rocks.
The Paleozoic sediments are composed mostly of beds of shales (laminated sediments consisting mostly of particles of clay) and sandstones in which strata of limestone occur in places.
Unfortunately, decades of corruption, mismanagement, and military rule stymied growth and achievement.
By the 1990s, though, the country’s state of affairs began showing signs of improvement, and Ghana is now held up as an example of successful economic recovery and political reform in Africa.
South of Kumasi, in the south-central part of the country, is Ghana’s only true natural lake—Bosumtwi—lying in a meteorite impact crater and without any outlet to the sea.