While details surrounding the invention of the first bridge have been lost to time, a bridge in the Palk Straight is believed to be the oldest ever discovered. The first signs of civilization in the region date back 1,750,000 years ago, and the bridge is believed to be as old.
Images from space reveal a bridge along a chain of shoals spanning about 18.6 miles. The unique curvature and composition of the bridge reveal that it was man-made. According to Guinness World Records, the oldest bridge still in use today is a bridge in Turkey that dates back to 850 B.C.