Ghana’s administrative capital is the coastal city of Relief throughout Ghana is generally low, with elevations not exceeding 3,000 feet (900 metres).
These ranges are part of the Accra Plains, which are underlain by some of the oldest Precambrian rocks known—mostly gneisses (coarse-grained rocks in which bands containing granular minerals alternate with bands containing micaceous minerals); in places they rise above the surface to form inselbergs (prominent steep-sided hills left after erosion).
The only extensive areas of young rocks less than about 136 million years old are in the wide, lagoon-fringed delta of the Volta, about 50 miles (80 km) east of Accra, and in the extreme southwest of the country, along the Axim coast.
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.