|Native name||Airé (Riyan)|
|Other name(s)||Egre (Kadic)|
|River system||Acre Basin|
|Main source||Kuridan, Metni (Mount Metni)|
1,822 m (5,978 ft)
0 m (0 ft)
|Countries||Kadya, Lugida, Riyana|
|Cities||Cuáma, Rogue, Sévmiela|
|Length||1,058 km (657 mi)|
|Inland ports||Port of Rogue|
The Acre or Iris (Riyan: Airé /ɪˈrɛ/) is a major river in Soltenna. It rises at the Kuridan Pass near Mount Metni and flows west through Lugida, Kadya, and Riyana before reaching its estuary near Cuáma out into the Amiyant Sea. At 1,058 kilometres (657 mi), the Acre is Soltenna's sixth longest river. With the Cuáma River, the Acre comprises the Central Basin area, whose drainage basin encompasses much of Kadya and Riyana.
The Acre and Cuáma rivers have played a major role in Soltennan history, and in early ancient times had been the most prosperous region in the subcontinent. Throughout history, the Acre has been used for water, irrigation, sanitation, industry, transportation, and war. Its basin is site to a number of earliest known civilizations, most notably the Wa Dynasty and Ancient Iris. Along the river basin, Cuáma, Sévmiela, and Rogue are each home to over three million.
The Acre is important to the ethnocultural origins of modern East Soltenna. Proto-Rietic peoples are theorized to have originally inhabited the Upper Acre area by at least 3,000 BCE, prior to the onset of Rietic migrations. Early Rietic tribes founded the (Name) Dynasty, a small city-state in Gárnn-Ann in 2,500 BCE. Down the river, another Rietic tribe founded the First Iris in Sémliam on around 2,000 BCE. The Lower Acre basin was inhabited by early Kwangs, who in 2,500 BCE formed the Wa Dynasty and secured their presence in Cuáma.