Rising 552 feet above the Straits of Mackinac, where lakes Michigan and Huron meet, is the world-famous Mackinac Bridge. Also known as the "Mighty Mac," this engineering marvel is 5 miles long and, anchor block to anchor block, holds the record as the longest suspension bridge in the world. Before the Mackinac Bridge was constructed, travelers between Michigan's upper and lower peninsulas had to cross the Straits via an an hour-long ferry ride.