Palácio de Ferro is located in the capital city with a population over what figure?
Palácio de Ferro: Palácio de Ferro (English: Iron Palace ) is a historical building in the Angolan capital Luanda, "believed to be designed and built by – or by someone associated with – Gustave Eiffel", builder of the world-famous icons, the Eiffel Tower in Paris and the Statue of Liberty in New York City. Luanda:  It has a metropolitan population of over 6 million.
6 million