Ancient earthen structures in Ohio become a UNESCO World Heritage Site

Scattered throughout Central Ohio are earthworks that are believed to have been constructed by ancient indigenous people for ceremonial or spiritual purposes up to two thousand years ago. Several, including some burial mounds, are protected as part of Hopewell Culture National Historical Park. And now, they have been designated a UNESCO World Heritage Site. Correspondent Conor Knighton explores the grandeur of these mysterious complexes.