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River in central Portugal
Isna River (Portuguese: Rio Isna, Portuguese pronunciation: [ˈiʒnɐ]) is a river in Portugal. It is 45.5 kilometres (28.3 mi) long.
The river's source begins South of Casalinho and then passes South West past the villages/towns of Atalaia, Cardal Pequeno, Fernandaires and Trisio before it leads into the Zêzere River.
References
"Rio Isna". snirh.inag.pt (in Portuguese). Archived from the original on 2013-04-16. Retrieved 2012-09-20.