 References to the predynastic rulers of Copán are found in later texts, but none of these texts predate the refounding of Copán in AD 426.The fertile Copán River valley was long a site of agriculture before the first known stone architecture was built in the region about the 9th century BC.The city was important before its refounding by a foreign elite; mentions of the predynastic history of Copán are found in later texts, but none of these predates the refounding of the city in AD 426.