what county is monaca pa in
Monaca, PA. Sponsored Topics. Monaca ( /mÉ¨nÃ¦kÉ/ mi-nak-É) is a borough in Beaver County, Pennsylvania, United States along the Ohio River, 25 miles (40 km) northwest of Pittsburgh. Monaca was first incorporated as Phillipsburg in 1840, and had been known by that name since the 1820s.