 Excavation unearthed a pyramid built in multiple layers.This is the spot where, according to legend, the Aztecs saw their sign to settle from their wanderings, an eagle perched on a nopal cactus with a snake in its beak, which is still the symbol of Mexico today.The Nacional Monte de Piedad building is the national pawn shop, founded in 1775 and one of the largest second-hand shops in the world.