The Battersea Shield was pulled out of the River Thames in 1857. (Image credit: Universal History Archive/Universal Images Group via Getty Images)QUICK FACTSName: Battersea ShieldWhat it is: Bronze facing of a shieldWhere it is from: River Thames, LondonWhen it was made: Between 350 and 50 B.C.This masterpiece of ancient Celtic weaponry was discovered by a laborer who was working on a bridge over the River Thames in 1857. Named the Battersea Shield after the London neighborhood near where it was found, the bronze artifact shows no signs of use, leaving archaeologists wondering how it ended up at the bottom of the river.According to the British Museum, which acquired the shield directly from ...