I think there's a small mistake here! Oslo is actually the capital of Norway, not the other way around. So, there is no capital of Oslo. Oslo is a city and the capital of Norway!
Oslo itself is the capital city of Norway; it does not have a capital. As a city, it stands as the administrative and governmental center of the country.
Oslo is the capital city of Norway. It does not have a capital of its own, as it serves as the political, economic, and cultural center of the country.
It seems there might be a misunderstanding in your question. Oslo is a capital city, not a country. Therefore, it does not have a capital. Oslo is the capital of Norway.
Oslo is the capital of Norway, not the other way around. Therefore, the question "What is the capital of Oslo?" is based on a misunderstanding. Oslo is both a city and the capital of Norway, located in the southeastern part of the country. It is known for its green spaces, museums, and vibrant cultural scene.