Kruszwica's collegiate church is one of the oldest Polish monuments, still representing Romanesque style and one of the few who retained the original style of the present day.
The interior of the temple, like the outer body itself, is raw and devoid of any excesses. There is a baptismal font and a bower, and in the apse the traces of the original altars can be seen. The temple built of sandstone and granite has been restored, and the only change that was made in the original design was a slight widening of the windows. The structure is complemented by a single tower, which replaced two earlier in the sixteenth century. There are many symbolic crosses in the interior, including a characteristic, ancient swastika - the sign of protection against Satan. During renovations, remnants of the stained glass windows and ceramic tiles have been discovered, which may indicate that the church's furnishings have been richer in the past. On the walls of the church you can also see numerous apsees, some bas-reliefs and stone signs preserved from the time of the building.