The port at the Lower Niger Valley that once served as a major gateway to Nigeria's export import trade was?

The port at the Lower Niger Valley that once served as a major gateway to Nigeria's export import trade was Warri. Warri is a city located in the southwestern part of Nigeria, in the Niger Delta region. The city is located at the confluence of the Warri River and the Forcados River, which provides access to the Atlantic Ocean. Warri was an important port for the export of palm oil and other commodities from Nigeria during the colonial period, and it played a significant role in the country's economy. Today, Warri remains an important industrial and commercial center in Nigeria, with a major oil refinery and other industries located in the city.