If I were a multibillionaire with money to burn, I would fund a planet-wide lidar scan. So much of our history could be hidden beneath waves, jungles and snow.
Imagine all what they'll discover when there's a way to reliably scan the earth with neutrinos
There is already a similair tehnique called muography which uses muons and has already been used for scanning the pyramids in Gizah and currently for the Mayan pyramids in Chichen Itza amongst others. Pretty SF stuff!