Researchers have shown that the smallest possible canonical volume of a smooth complex projective three‑fold of general type is exactly 1/420. This minimum is reached on a smooth model of the hypersurface X₄₆ ⊂ P(4,5,6,7,23). The proof uses canonical‑ring techniques, basket packing, and constructions of invariant pluricanonical pencils tied to absolute two‑forms. It sharpens earlier lower bounds of 1/3, 1, and 2, confirming that 1/420 is the absolute minimum for this class of varieties. The result applies only to smoothly embedded projective three‑folds of general type and does not extend to singular or non‑projective cases.