What is the miniature world that Conrad creates within the Heart of Darkness both psychologically and geographically?

The Congo and the 'soul' or consciousness. Oliver Stone attempts to fast-forward the treatment upon S.E. Asia and Kurtz, I believe, and the same story, in my view, possibly is Edgar Allen Poe's 'Pit and Pendulum'. You may not remember or learn any of it, without uncapping a Russian Doll, then lining the dolls from largest to tiniest. Something inside, until there is nothing. Mircrocosms abound! ___________ It may be the 'heart of darkness', that is the potential for utter savagery within all of us. At the same time it's worth bearing in mind that there is a strong political (anti-imperialist) dimension to the novel (novella). From 1885-1908 the "Congo Free State" was the personal property of the King of the Belgians. It's estimated that at least five million Africans were murdered by his private army of thugs.