The Deepest Known Trench Holds Enough Water to Cover Earth
If the Mariana Trench were filled with all of Earth's ocean water, it would still overflow by several kilometers. The trench plunges nearly eleven kilometers below sea level and remains largely unexplored.
💡 Fun detail:
At that depth the pressure is equal to the weight of about fifty jumbo jets stacked on a single postage stamp.
Source: NOAA