The Church of St. Onuphrius in Posada Rybotycka is a fortified masonry church dating from the 14th to the 16th century, located in the Fredropol municipality of Przemysl County. It is the oldest preserved church in Poland, originally Orthodox and, since 1692, Greek Catholic. The church is characterized by three interconnected towers and hipped roofs, while its thick stone walls feature loopholes, underscoring its defensive nature. The oldest section—the presbytery with Gothic gables—dates back to the turn of the 14th and 15th centuries, while the square nave with its defensive tower originates from the 15th century. The western part, dated to the early 16th century, was built as a defensive tower housing the narthex and the babinets (women's gallery), with a chapel for monks on the upper floor. This section preserves inscriptions carved in Latin and Ruthenian from the years 1506 and 1514, which, though now considered acts of vandalism, attest to the long history of the site. The church was associated with the Basilian monastery until the 18th century, after which it became a parish church. According to tradition, the last Orthodox bishop of Przemysl, Michał Kopystyński, is buried in its crypts. After the displacement of the local population in 1945, the church was devastated and stripped of its interior furnishings. Renovations in the 1960s and 1980s uncovered 16th-century Byzantine-style polychrome paintings. Today, the church serves as a branch of the National Museum of the Przemysl Land and was transferred to the Fredropol municipality in 2010. The Church of St. Onuphrius stands as a significant cultural and historical monument of the region, attracting both architecture enthusiasts and tourists.