" An anvil dropped from the sky falls for nine nights, and on the tenth it reaches the earth; and likewise it falls nine nights and days from the earth, and on the tenth day it reaches Tartaros. Tartaros is surrounded by an iron wall. Three times this stronghold is encompassed by Night. Over it grew the roots of the earth and sea. Within it the Titans are hidden in darkness, and can never escape; for it was Poseidon who set the iron doors around them. "

― Karl Kerényi , The Gods of the Greeks