Aryaru

Aryaru, known in Cham sources as Aia Ru, was a coastal region of Champa around Phú Yên. Its river plains lie between the mountains of the interior and the sea, while Cham religious sites attest to a long history of settlement. The area remained under Cham rule into the seventeenth century, although Vietnamese migrants had already moved south across the frontier.

In 1611 the Nguyễn rulers sent an army south and annexed much of Aia Ru. Cham and Vietnamese accounts present the fighting from different sides, but the result was a lasting shift of the frontier. Vietnamese authority was established in Phú Yên while the Cham polity continued farther south, with its heartland around Panduranga. The older sacred sites remained as evidence of the region's Cham past.

The later city of Tuy Hòa lies here.