The church is regarded as Svendborg's principal church and it is dedicated to the seafarers' patron saoint St. Nicholas. It is built of brick in the early 13th century and is in its design inspired by north German architecture. The church of today is a three nave-Roman bacilica. The oldest part of the church is the basilica itself with centre- and aisle naves in red medieval red brick. At the end of the 15th century the big square tower was built to the west. The tower's present copper-clad lantern spire appeared in 1763.