1911 Encyclopædia Britannica/Ostra
OSTRA, an ancient town of Umbria, Italy, near the modern Montenovo, S.E. of Sena Gallica (Sinigaglia). It is hardly mentioned by ancient authors, but excavations have brought to light remains of various buildings and some inscriptions exist. Pliny mentions with it another ancient town, Suasa, 5 m. W., which also did not survive the classical period.