The Pool Malebo (formerly Stanley Pool, also known as Malebo Pool, or Lake Nkunda by local indigenous people in pre-colonial times), is a lake-like widening in the lower reaches of the Congo River. Facing each other on opposite banks of the Pool are the national capitals of "the two Congos".
The Pool Malebo is about 35 km (22 mi) long, 23 km (14 mi) wide and 500 km². Its central part is occupied by M'Bamou or Bamu Island (180 km²), which is Republic of the Congo territory. The pool is shallow with depths of 3 to 10 m, while water levels vary by as much as 3 m over the course of a year at an average altitude of 272 m (900ft).
The capital of the Democratic Republic of the Congo, Kinshasa, and the capital of the Republic of the Congo, Brazzaville, are located on opposite shores of Pool Malebo which makes them the two closest capitals in the world.