it's not southwest nigeria - more south central. it has been a capital city, but then of another state for a short time.
as far as i know it has nothing to do with an oil spil, but i don't know the full story, i'll try to find out
it seems that the artist is known for photography and this is an installation, or living sculpture, they are intended to resemble film sets and the verisimilitude of that world in this place