Osun State in the context of Mona monkey

Kwara (Yoruba: Ìpínlẹ̀ Kwárà) is a state in Western Nigeria, bordered to the east by Kogi State, to the north by Niger State, and to the south by Ekiti, Osun, and Oyo states, while its western border makes up part of the international border with Benin. Its capital is the city of Ilorin and the state has 16 local government areas.

Of the 36 states of Nigeria, Kwara is the ninth largest in area but the sixth least populous with an estimated population of about 3.2 million as of 2016. Geographically, Kwara is split between the West Sudanian savanna in the east and the Guinean forest–savanna mosaic ecoregion in the rest of the state. Important geographic features include rivers with the Niger flowing along the northern border into Lake Jeba before continuing as the border while the Awun, Asa, Aluko, and Oyun rivers flow through the interior. In the far northwest of the state is the Borgu section of the Kainji National Park, a large national park that contains populations of grey heron, kob, hippopotamus, African bush elephant, olive baboon, and roan antelope, along with some of the last remaining West African lions on earth. In the far southwest, a small part of the Old Oyo National Park contains crowned eagle, martial eagle, African buffalo, oribi, and patas monkey populations.

The South West (often hyphenated to the South-West) is one of the six geopolitical zones of Nigeria representing both a geographic and political region of the country's southwest. It comprises six states — Ekiti, Lagos, Ogun, Ondo, Osun, and Oyo.

The zone stretches along the Atlantic seaboard from the international border with Benin Republic in the west to the South South in the east with the North Central to the north. The South West is split with the Central African mangroves in the coastal far south while the major inland ecoregions are the Nigerian lowland forests ecoregion in the south and east along with the Guinean forest–savanna mosaic ecoregion in the drier northwest. The weather conditions vary between Nigeria's two, distinctive seasons; the rainy season (March - November) and the dry season named the Harmattan (from November - February). The Harmattan is a dry and dusty northeasterly trade wind (of the same name), which blows from the Sahara over West Africa into the Gulf of Guinea. During this season, the wind transports the eponymous Harmattan dust, particles of fine Saharan sand.

The Yorùbá religion (Yoruba: Ìṣẹ̀ṣe [ìʃɛ̀ʃē]), West African Orisa (Òrìṣà [òɾìʃà]), or Isese (Ìṣẹ̀ṣe), comprises the traditional religious and spiritual concepts and practice of the Yoruba people. Its homeland is in present-day Southwestern Nigeria and Southern Benin, which comprises the majority of the states of; Oyo, Ogun, Osun, Ondo, Ekiti, Kwara, Lagos and parts of Kogi in Nigeria, the Departments of; Collines, Oueme, Plateau in Benin, and the adjoining parts of central Togo, commonly known as Yorubaland (Yoruba: Ilẹ̀ Káàárọ̀-Oòjíire). It has become the largest indigenous African tradition / belief system in the world with several million adherents worldwide.

It shares some parallels with the Vodun practised by the neighbouring Fon and Ewe peoples to its west and with the religion of the Edo people to its east. Yorùbá religion is the basis for several religions in the New World, notably Santería, Umbanda, Trinidad Orisha, and Candomblé. Yorùbá religious beliefs are part of Ìtàn (history), the total complex of songs, histories, stories, and other cultural concepts which make up the Yorùbá society.

The Law of Nigeria consists of courts, offences, and various types of laws. Nigeria has its own constitution which was established on 29 May 1999. The Constitution of Nigeria is the supreme law of the country. There are four distinct legal systems in Nigeria, which include English law, Common law, Customary law, and Sharia Law. English law in Nigeria is derived from the colonial Nigeria, while common law is a development from its post-colonial independence.

Customary law is derived from indigenous traditional norms and cultural practices, including the dispute resolution meetings of pre-colonial Yoruba land secret societies and the Èkpè and Okónkò of Igboland and Ibibioland. Sharia Law (also known as Islamic Law) used to be used only in Northern Nigeria, where Islam is the predominant religion. It is also being used in Lagos State, Oyo State, Kwara State, Ogun State, and Osun State by Muslims. The country has a judicial branch, the highest court of which is the Supreme Court of Nigeria.

Ogun StateListen (Yoruba: Ìpínlẹ̀ Ògùn [ìk͡pĩ́lɛ̀ ògũ̀]) is a state in southwestern Nigeria. It is bordered to the south by Lagos State and the Bight of Benin, to the east by Ondo State, and to the north by Oyo and Osun states while its western border forms part of the national border with the Republic of Benin. The capital and largest city is Abeokuta, and the state is divided into 20 local government areas.

Of the 36 states in the country, Ogun is the 24th largest in area but among the top fifteen most populous, with an estimated population of about 6.4 million as of 2020. Geographically, the state lies primarily in the tropical Nigerian lowland forests ecoregion, although parts of the state's north transition into the Guinean forest–savanna mosaic and some of the coastal south reach the Central African mangrove ecoregion. The Ogun and Yewa rivers are the state's major waterways while the Omo Forest Reserve in the southeastern part of the state is one of the most important conservation areas in the country—home to a variety of bird species along with some of Nigeria's last remaining Nigeria-Cameroon chimpanzee and African forest elephant populations.

The Oṣun River (sometimes spelt Oshun), Yoruba: Odò Ọ̀ṣun, is a river of Yorubaland that rises in Ekiti State and flows westwards into Osun State before turning southwestwards at its confluence with the Erinle River near the town of Ede and then heading south at the Asejire reservoir flowing though the rest of the state and Ogun State in Southwestern Nigeria before eventually discharging into the Lekki Lagoon and the Atlantic at the Gulf of Guinea.

The river is named after the Oṣun or Oshun, one of the most popular and venerated Orishas. The annual traditional worship at the Ọṣun Shrine near the Ọṣun River at Osogbo has become a popular pilgrimage and important tourist attraction, drawing people from all over Nigeria and abroad to the annual festival in August.

The former Western State of Nigeria was formed in 1967 when the Western Region was subdivided into the states of Lagos and Western State. Its capital was Ibadan, which was the capital of the old region. The largest ethnic group here are the Yoruba.

In 1976, the state was subdivided into three new states, Ogun, Ondo and Oyo. The region now consists of nine states, across three geopolitical zones: Delta, Edo, Ekiti, Kwara, Lagos, Ogun, Ondo, Osun, and Oyo States.

Ekiti listen(Yoruba: Ìpínlẹ̀ Èkìtì) is a state in southwestern Nigeria, bordered to the North by Kwara State for 61 km, to the Northeast by Kogi State for 92 km, to the South and Southeast by Ondo State, and to the West by Osun State for 84 km. Named for the Ekiti people—the Yoruba subgroup that makes up the majority of the state's population—Ekiti State was carved out from a part of Ondo State in 1996 and has its capital as the city of Ado-Ekiti.

One of the smallest and most educated states with the highest number of professors in Nigeria, Ekiti is the 31st largest in the area and 30th most populous with an estimated population of nearly 3.5 million as of 2022. Geographically, the state is divided between the Nigerian lowland forests in most of the state and the drier Guinean forest–savanna mosaic in the north. Among the state's nature are false acraeas, mona monkey, forest buffalo, and grey parrot populations along with one of the last remaining Nigeria-Cameroon chimpanzee populations with a troop of about 20 chimpanzees in the heavily threatened Ise Forest Reserve. In March 2022, Ekiti State became the first state in Nigeria to adopt a state tree as one of its official symbols. On World Forest Day 2022, Governor Kayode Fayemi announced that Obeche (Triplochiton scleroxylon) had been chosen as State Tree owing to its local prominence and environmental, economic and cultural significance.

Oyo Listen(Yoruba: Ìpínlẹ̀ Ọ̀yọ́ [ìk͡pĩ́lɛ̀ ɔ̀jɔ́]) is a state in southwestern Nigeria. Its capital is Ibadan, the third most populous city in the country and formerly the second most populous city in Africa. Oyo State is bordered to the north by Kwara State for 337 km, to the southeast by Osun State for 187 km, partly across the River Osun, and to the south by Ogun State, and to the west by the Republic of Benin for 98 km. With a projected population of 7,976,100 in 2022, Oyo State is the sixth most populous in the Nigeria.

The vast majority of Oyo State residents are Yoruba. Nicknamed the "Pace Setter State", present-day Oyo State sits on territory formerly ruled by the Oyo Empire. The Oyo Empire was a powerful Yoruba empire that ruled much of Oyo state and by extension major parts of Yoruba lands from c. 1300 to 1896. Built in the 1830s, the modern city of Oyo "New Ọyọ" (Ọ̀yọ́ Àtìbà) is considered a remnant of the imperial Oyo era to distinguish itself from the former capital to the north, 'Old Oyo' (Ọ̀yọ́-Ilé). Although the medieval great Oyo empire collapsed in 1835, The Alaafin (owner and custodian of the palace) continues to serve a ceremonial role in the new city of Oyo in present Oyo state.