It’s called “the city beneath the city”: the myriad tunnels and chambers of the Detroit salt mines comprise one ... See, we live in the Michigan Basin, an area once covered with salt water ...

so we decided to take a deep dive into the epic salt mines below our feet. Michigan Basin Map (Detroit Salt Company) According to the Detroit Salt Company, 400 million years ago, ocean water ...

ClickOnDetroit readers frequently submit questions about the salt mines through our 4YI form ... an area known as the Michigan Basin. As the water evaporated it left behind large deposits of ...