I've been to the Mariana Trench. The choice is clear: Protect one of earth's last frontiers or destroy it before we even understand what we're losing.

If you traveled to the deepest points of Earth, what would you find? Lost cities, mythical sea monsters, rivers of gold? Probably not. But there is still a lot to discover. So join me as we travel ...

Half of Earth’s oceans are more than 3.2km deep. Beneath them lie cavernous plains untouched by sunlight, vast gaping trenches made by Earth’s tectonic plates shifting, and ranges of underwater ...