Santa Criz is a Roman archaeological site, located in the foothills of the Sierra de Arbiñaga. There has been an Iron Age fort already before Romans arrival. The Roman forum and surrounding town was established in the first century BCE during Augustus Caesar. To the south of the city is a necropolis. It occupies about 2000 m².
The church of the former Franciscan monastery was built probably between 1515 and 1520. It is located in the UNESCO World Heritage Site of Old Rauma. The church stands by the small stream of Raumanjoki (Rauma river).
The exact age of the Church of the Holy Cross is unknown, but it was built to serve as the monastery church of the Rauma Franciscan Friary. The monastery had been established in the early 15th century and a wooden church was built on this location around the year 1420.
The Church of the Holy Cross served the monastery until 1538, when it was abandoned for a hundred years as the Franciscan friary was disbanded in the Swedish Reformation. The church was re-established as a Lutheran church in 1640, when the nearby Church of the Holy Trinity was destroyed by fire.
The choir of the two-aisle grey granite church features medieval murals and frescoes. The white steeple of the church was built in 1816 and has served as a landmark for seafarers.