Serpent Mound is the world’s largest surviving effigy mound—a mound in the shape of an animal—from the prehistoric era. Located in southern Ohio, the 411-meter-long (1348-feet-long) Native American structure has been excavated a few times since the late 1800s, but the origins of ...read more
On February 27, 1964, the Italian government announces that it is accepting suggestions on how to save the renowned Leaning Tower of Pisa from collapse. The top of the 180-foot tower was hanging 17 feet south of the base, and studies showed that the tilt was increasing by a ...read more