Iru hillfort

The Iru hillfort (Estonian: Iru linnamägi or Iru Linnapära) is an ancient hillfort located in Tallinn, Estonia. First established in the Bronze Age, it was a major hillfort in Ancient Estonia, and is on the banks of the Pirita river near to Estonia's northern coast. The Iru hillfort was at the height of its prosperity during the Viking Age, before starting to decline in the 10th century as settlement grew in Tallinn Old Town. Iru is commonly described as the predecessor of the modern Estonian capital Tallinn, and today lies within Tallinn's city limits.