The World''s Largest Granite Quarry | Portland Rock .
Jul 11, 2013· The World''s Largest Granite Quarry. Mount Airy is a small North Carolina town that boasts the largest granite quarry in the world, which is affectionately known to locals as "The Rock." People have been mining the quarry for 120 years, and it has produced granite that has been used to build memorials such as the WWII .