Question: Who was the first European to sail around the southern tip of the continent where the river draining the southwest plain of the Congo is located?

full_context: Document 1: Cape of Good Hope: When following the western side of the African coastline from the equator, however, the Cape of Good Hope marks the point where a ship begins to travel more eastward than southward. Thus, the first modern rounding of the cape in 1488 by Portuguese explorer Bartolomeu Dias was a milestone in the attempts by the Portuguese to establish direct trade relations with the Far East (although Herodotus mentioned a claim that the Phoenicians had done so far earlier). Dias called the cape Cabo das Tormentas (``Cape of Storms ''; Dutch: Stormkaap), which was the original name of the`` Cape of Good Hope''.
Document 2: Bartolomeu Dias: Bartolomeu Dias (Portuguese pronunciation: (baɾtuluˈmew ˈdi. ɐʃ); Anglicized: Bartholomew Diaz; c. 1451 -- 29 May 1500), a nobleman of the Portuguese royal household, was a Portuguese explorer. He sailed around the southernmost tip of Africa in 1488, reaching the Indian Ocean from the Atlantic, the first European known to have done so.
Document 3: History of the Cape Colony before 1806: The written history of the Cape Colony in what is now South Africa began when Portuguese navigator Bartolomeu Dias became the first modern European to round the Cape of Good Hope in 1488. In 1497, Vasco da Gama sailed along the whole coast of South Africa on his way to India, landed at St Helena Bay for 8 days, and made a detailed description of the area. The Portuguese, attracted by the riches of Asia, made no permanent settlement at the Cape Colony. However, the Dutch East India Company (VOC) settled the area as a location where vessels could restock water and provisions.
Document 4: Geography of Cambodia: Cambodia's low mountain ranges - representing the walls of the bowl - remain as the result of only rather recent substantial infrastructural development and economic exploitation - in particular in remote areas - formidably forested. The country is fringed to the north by the Dangrek Mountains plateau, bordering Thailand and Laos, to the north - east by the Annamite Range, in the south - west by the Cardamom Mountains and in the South by the Elephant Mountains. Highlands to the north - east and to the east merge into the Central Highlands and the Mekong Delta lowlands of Vietnam.
Document 5: Spice trade: The first country to attempt to circumnavigate Africa was Portugal, which had, since the early 15th century, begun to explore northern Africa under Henry the Navigator. Emboldened by these early successes and eyeing a lucrative monopoly on a possible sea route to the Indies the Portuguese first crossed the Cape of Good Hope in 1488 on an expedition led by Bartolomeu Dias. Just nine years later in 1497 on the orders of Manuel I of Portugal, four vessels under the command of navigator Vasco da Gama rounded the Cape of Good Hope, continuing to the eastern coast of Africa to Malindi to sail across the Indian Ocean to Calicut, on the Malabar Coast. in south India -- the capital of the local Zamorin rulers. The wealth of the Indies was now open for the Europeans to explore; the Portuguese Empire was the earliest European seaborne empire to grow from the spice trade.
Document 6: Portuguese discovery of the sea route to India: One of the sailors, Bartolomeu Dias passed the southernmost point of Africa known as the Cape of Good Hope in 1488. He declared it possible to travel to India by going around Africa. The Portuguese were then able to make an immense profit by using their own ships to retrieve the spices.
Document 7: Yumbi: Yumbi is a town and territory in Plateaux District of Bandundu Province in the Democratic Republic of the Congo. It lies on the eastern bank of the Congo River between Bolobo and Lukolela.
Document 8: Mitumba Mountains: The Mitumba Mountain range stretches along the Western Rift Valley in Eastern Congo (DRC), west of lake Tanganyika. The two main peaks, Mount Kahuzi (3,308 m) and Mount Biéga (2,790 m) are extinct volcanoes.
Document 9: Congo River: Railways now bypass the three major falls, and much of the trade of Central Africa passes along the river, including copper, palm oil (as kernels), sugar, coffee, and cotton. The river is also potentially valuable for hydroelectric power, and the Inga Dams below Pool Malebo are first to exploit the Congo river.
Document 10: Republic of the Congo: The Republic of the Congo's sparse population is concentrated in the southwestern portion of the country, leaving the vast areas of tropical jungle in the north virtually uninhabited. Thus, Congo is one of the most urbanized countries in Africa, with 70% of its total population living in a few urban areas, namely in Brazzaville, Pointe-Noire or one of the small cities or villages lining the 534-kilometre (332 mi) railway which connects the two cities. In rural areas, industrial and commercial activity has declined rapidly in recent years, leaving rural economies dependent on the government for support and subsistence.
Document 11: Republic of the Congo: The southwest of the country is a coastal plain for which the primary drainage is the Kouilou-Niari River; the interior of the country consists of a central plateau between two basins to the south and north. Forests are under increasing exploitation pressure.
Document 12: Mayombe: Mayombe (or Mayumbe) is a geographic area on the western coast of Africa occupied by low mountains extending from the mouth of the Congo River in the south to the Kouilou-Niari River to the north. The area includes parts of the Democratic Republic of the Congo, Angola (Cabinda Province), the Republic of the Congo and Gabon.
Document 13: Republic of the Congo: Congo is located in the central-western part of sub-Saharan Africa, along the Equator, lying between latitudes 4°N and 5°S, and longitudes 11° and 19°E. To the south and east of it is the Democratic Republic of Congo. It is also bounded by Gabon to the west, Cameroon and the Central African Republic to the north, and Cabinda (Angola) to the southwest. It has a short coast on the Atlantic Ocean.
Document 14: Geography of Angola: Angola is located on the western Atlantic Coast of Central Africa between Namibia and the Republic of the Congo. It also is bordered by the Democratic Republic of the Congo and Zambia to the east. The country consists of a sparsely watered and somewhat sterile coastal plain extending inland for a distance varying from . Slightly inland and parallel to the coast is a belt of hills and mountains and behind those a large plateau. The total land size is . It has an Exclusive Economic Zone of .
Document 15: Republic of the Congo: The Republic of the Congo (French: République du Congo), also known as Congo, Congo Republic, West Congo[citation needed], or Congo-Brazzaville, is a country located in Central Africa. It is bordered by five countries: Gabon to the west; Cameroon to the northwest; the Central African Republic to the northeast; the Democratic Republic of the Congo to the east and south; and the Angolan exclave of Cabinda to the southwest.
ground_truth: Bartholomew Diaz
sub_queries: Which river serves as drainage for the southwest plain of the Congo? Answer: Kouilou-Niari River
Kouilou-Niari River >> continent Answer: Africa
who was the first european to sail around the southern tip of Africa Answer: Bartholomew Diaz