The nave of the church was constructed at the beginning of the 11th century from tuff, a soft volcanic stone from the Rhein area of Germany. This was transported to Anloo in large boulders and sawn into pieces of the required size and shape on arrival.
At its base, the wall is more than a metre thick. A mortar made of crushed seashells was used as cement. The tuff stone walls were coated with whitewash both on the inside and out. In 1942, this whitewash was chipped off. The West side of the nave is now suffering from serious corrosion as a result of the weather. The small rounded windows located high in shallow niches in the wall indicate a Romanic style of architecture.