Silva Arsia

The Silva Arsia was the forest near Rome situated where the Roman and Veientine territories abutted. near Rome where Romans heard the prophetic voice of Silvanus in 509 BCE, foretelling their defeat of the Etruscans (Livy), 2.7.2). At the Battle of Silva Arsia that year the forces said to have been assembled by the Tyrrhenian Tarquin were defeated, though with the loss, traditionally, of the Roman consul Lucius Junius Brutus. The forest, rich in timber essential for shipbuilding, had been seized from the Etruscans of Veii by Ancus Martius.

Since woodland was everywhere the province of Silvanus, there is no reason to connect the otherwise unknown Silva Arsia with the "forest of Silvanus [Silvanus luccus] outside the walls at a distance, all overgrown with a willow grove" noted in Plautus' Aulularia 674.