The Hoover Dam is expected to be one of the last remaining visible structures from our species, and it contains a star map that if no other means were available, could be used to determine the exact date on which Hoover Dam was completed.
fact
The Hoover Dam is expected to be one of the last remaining visible structures from our species, and it contains a star map that if no other means were available, could be used to determine the exact date on which Hoover Dam was completed.