The capital city of the Republic of Congo is Brazzaville. Situated on the Congo River, Brazzaville serves as the political and administrative center of the country. It is one of Africa's oldest cities, founded in the late 19th century and named after the Italian explorer Pierre Savorgnan de Brazza. Today, Brazzaville is known for its vibrant culture, featuring a mix of modern and colonial architecture, bustling markets, and various cultural festivals. It shares a river border with Kinshasa, the capital of the Democratic Republic of the Congo, making them the closest capital cities in the world.