The hadal zone, mostly comprising of deep trenches and constituting of the deepest part of the world's oceans, represents the least explored habital but one of the last frontiers on our planet. The present scientific understanding of the hadal environment is still relatively rudimentary, particularly in comparison with that of shallower marine environments. In the last 30 years, continuous efforts have been launched in deepening our knowledge regarding the ecology of the hadal trench. However, the geological and environment of hadal trenches and offer a perspective of the hadal science involved therein. For the first time, we release high-definition images taken by a new full-ocean-depth manned submersible Fendouzhe that reveal novel species with an unexpectedly high density, outcrops of mantle and basaltic rocks, and anthropofenic pollutants at the deepest point of the world's ocean. We advocate that the hydration of the hadal lithosphere is a driving force that inflluences a variety of sedimentary, geochemical, and biological processes in the hadal trench. Hadal lithosphere might host the Earth's deepest subsurface microbial ecosystem. Future research, should focus on establishing the intrinsic linkage of the geology, biology, and environment of the hadal trenches.