Mexico
Guanajuato city was built over old silver mines, some of which are used as roads. The Mexico DF metro system has many underground pedestrian walkways connecting stations.
Read more about this topic: Underground City
Famous quotes containing the word mexico:
“I think New Mexico was the greatest experience from the outside world that I have ever had.”
—D.H. (David Herbert)
“Is this what all these soldiers, all this training, have been for these seventy-nine years past? Have they been trained merely to rob Mexico and carry back fugitive slaves to their masters?”
—Henry David Thoreau (1817–1862)