Mexico City is technically an artificial island. It was built by filling up a lake with dirt to create an island, and then making a city on top of that. The Spaniards then built a city on top of that city.
This is why the earthquakes are so severe, because the soil is basically the shlurpy stuff at the bottom of a lake.
It is well enough that people of the nation do not understand our banking and monetary system, for if they did, I believe there would be a revolution before tomorrow morning.
Henry Ford