1,100 ft. beneath the city of Detroit, Michigan lies a massive salt mine. Opened in 1910, it covers 1,500 acres and has over 100 miles of roads. – WTF Fun Facts
Source: https://en.wikipedia.org/wiki/Detroit_salt_mine
1,100 ft. beneath the city of Detroit, Michigan lies a massive salt mine. Opened in 1910, it covers 1,500 acres and has over 100 miles of roads. – WTF Fun Facts
Source: https://en.wikipedia.org/wiki/Detroit_salt_mine