The first Christian church was probably a wooden church. Of this church there is no trace, but the baptismal font in the Church today has probably belonged to this church. In the 1220s a new stone church of considerable size was built in round-headed Romanesque style and consisted of a nave with four pillars, chancel with two cross-arms and apse, an extension in the rear of the chancel where the altar was placed. A large tower in the west would be part of the building, but it never came to execution. The nave is left intact to this day. Lau church is the island’s largest country church. It is famous for its unique acoustics.
References: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.