The Democratic Republic of Congo has an incredibly diverse topography. It stretches from the fertile lowlands to the east, over the central basin where the Congo River flows, to the high mountains in the east and the southeast.
The eastern highlands of DR Congo, which border Rwanda and Uganda, are largely volcanic in origin. The mountains reach elevations of over 5,000 meters, and are characterized by steep slopes and deep valleys.
The central basin, through which the Congo River flows, is characterized by swampy lowlands and forests. The Congo River is the second-longest river in Africa and is one of the deepest and most powerful rivers in the world.
The western parts of DR Congo, stretching towards the Atlantic coast, are lower-lying and include the Kouilou-Niari-Songa depression, which is a region of low-lying coastal swamps, lagoons, and sandy beaches.
The highest point in DR Congo is Mount Stanley, which stands at 5,110 meters above sea level. It is located in the Rwenzori Mountains, which form part of the border between DR Congo and Uganda.
The lowest point in DR Congo is the Atlantic Ocean, which stands at sea level along the country's western coast.
See here a list of 10 cities in DR Congo and their elevation above sea level.