Detroit, Michigan, is the only American city from which one can travel due south through either the Detroit-Windsor Tunnel or over the Ambassador Bridge (pictured behind the "Boblo Boat") to reach Canada because of the fact Detroit is due north of Windsor, Ontario, Canada. This makes Detroit very uniquely situated since there is no other American city along the USA/Canada border from which one can travel due south to reach Canada.

Detroit is also known as "Motown" or "The Motor City" because it was once the city in which many American automobile manufacturers had their factories and/or headquarters, including GM, Dodge, & Chrysler, plus dozens more (here's a list: https://en.wikipedia.org/wiki/List_of_automobile_manufacturers_of_Michigan).

"Motown" was also the name of a uniquely American recording company famous for the "Motown" sound, which is a distinctive style of "soul" music with certain characteristics which include the use of tambourines with drums, a unique melodic & chord structure, bass instrumentation, & a singing style that originated in gospel music known as "call & response." This company was founded in Detroit by Berry Gordy, Jr. as "Tamla Records" on 01/12/59. He later changed the name of his company & incorporated as "Motown Record Corporation" on 04/14/60.

The name "Motown" is a combination of the words "motor" & "town," & since Detroit was already known as "The Motor City," it has also become a nickname for Detroit.

More Info: wikitravel.org