Ancient American geological formation, the Double Arch, suddenly collapsed on Wednesday, the National Parks Service said. Also known as the Toilet Bowl and the Hole in the Roof, the natural ...

Two ancient North American structures have collapsed within days of each other as a tribe has warned the 190-million-year-old geological feature is a 'bad omen'. The 'Double Arch'- also known as ...

light blue in model B); and one with a diamond-shaped keystone (the Gothic arch, model C). Flying buttresses act the same way ancient Roman columns did, countering the horizontal force of the arch.