**Explanation:**
Port Harcourt is located in Nigeria, specifically in the Niger Delta. The Niger Delta is the delta of the Niger River, which is the principal river in West Africa and the third-longest river in Africa, after the Nile and the Congo Rivers. It is located in the southern part of Nigeria, where the Niger River empties into the Gulf of Guinea.

**Details:**
- The Niger River is a major river in West Africa. It flows through multiple countries, including Guinea, Mali, Niger, and Nigeria.
- The Niger River has a vast delta area where it meets the Atlantic Ocean, known as the Niger Delta. The delta covers an area of about 20,000 square kilometers (7,700 square miles).
- Port Harcourt is the capital and largest city of Rivers State in Nigeria. It is an important industrial and commercial center in the Niger Delta region.
- The city of Port Harcourt is located along the Bonny River, which is one of the distributaries of the Niger River. The Bonny River flows into the Gulf of Guinea, and Port Harcourt is situated on the eastern bank of this river.
- The Niger Delta region is known for its rich oil and gas reserves, and Port Harcourt plays a significant role in Nigeria's oil industry. It is home to several oil refineries and serves as a major hub for oil and gas activities in the country.

**Conclusion:**
In conclusion, Port Harcourt is located in the Niger Delta, which is the delta of the Niger River. The Niger Delta is an important region in Nigeria, known for its oil and gas resources, and Port Harcourt serves as a major city and industrial center in this region.