Nimba County is a county in northeastern Liberia that shares borders with the Republic of Côte d'Ivoire in the East and the Republic of Guinea in the Northwest. Its capital city is Sanniquellie and its most populous city is Ganta. With the county's area measuring 11,551 square miles, Nimba is the largest of Liberia's 15 counties. The county has six statutory distriā¦Nimba County is a county in northeastern Liberia that shares borders with the Republic of Côte d'Ivoire in the East and the Republic of Guinea in the Northwest. Its capital city is Sanniquellie and its most populous city is Ganta. With the county's area measuring 11,551 square miles, Nimba is the largest of Liberia's 15 counties. The county has six statutory districts. As of the 2022 Census, it had a population of 621,841, making it the second most populous county in Liberia.