The tower is a nice example of the Late Gothic style. The building is made of brick, enlivened with sandstone. Against the north east corner there is a small tower for the staircase, which rises over the second section. It is covered with a pyramid top.
The buttresses (contre forts) are placed to strengthen the corners and from the second branch they have a triangle shape with small towers as decoration (pinnacles) on the dilutions. On top of the second dilution there should have been a parapet. There is not much more than a few extending supporting bricks, so called collar stones, that are decorated with gold-foil. From the collar stones that are still present and the other parts one could discover the shape and the architecture of the balustrades.
During a certain period the balustrade was partly a wooden gate. During the restoration of 1936-1938 the balustrade was remade out of stone.
From the highest part of the tower there wasn’t much left. Nevertheless the architecture of the windows and the profile could be reduced, so they could use them to restore. This branch was decorated with continuous mountain stone-blocks. The balustrade on this section was placed in the 18th century. The upper part of the tower is during the restoration of 1936 -’38 closed with a arc wall frieze. On top the frieze is a sandstone cornice (masking frame) with a circular bronze bar fixed.
On the north east corner there is a staircase tower, that extends a little above the second section. This small tower is covered with a pyramid roof. In this small tower there is a sandstone winding stairs, which has steps that form a screw archway. The lowest three steps are authentic, but the following twenty-one steps were forever smashed, probably in the Spanish period at the end of the 16th century. After this period this part of the stair was made of wood. During the big restoration the stair was again repaired like it was before.
To reach the balustrade, you have to climb another 85 steps. To reach the flat roof you have to climb once again 46 steps on the stair of stone, that is fixed in de south east wall. The flat roof offers a panoramic view over the landscape of Waterland.
The entrance is located in a small niche in the west wall, surrounded by a frame of crockets and finials. The niche itself has a richly ornamented and profiled frames, reveal sides, which originally included a tracery window. This window was till 1938 bricked up and since then provided with a stained glass window with the heraldic figures of Amsterdam and Ransdorp. On both ends of the entrance there are canopies and remains of small columns used to put figurines on top. The doors of oak now were applied in 1938 and that did give the entrance a more complete Late Gothic style.
The inner side of the tower was maintained very well in general. The first section must have been crossed in the past with a vault. Not much was left of this vault, only the with leaf work ornamented corbel stones. During the great restoration a cross vault was applied again. Inthe north and south wall high niches with fish bladder tracings are saved. The frames of these niches reach up from a horizontal frame carried by four round arches, that rest on a lot of cut corbel stones. Only one of them is decorated with sculpture.
That is the central corbel stone against the north wall. That sculpture does have an image of the Lamb of God with a cross vane. On the knees of the lamb climbs up a little mouse. On the east wall close to the entrance of the church there still is present a fragment of a stoup of natural stone. In one of the spindle part of the spiral staircase is engraved a master sign. In
the corbel stone where also the Lamb of God is engraved, there is another master sign in a cross vane. It is not known whom these two master signs are from.
In the south wall on a height of approximately 4,5 meters there is a niche. This niche is about 50 cm high, 60 cm deep and can be closed with three doors, one of copper, one wooden with iron fittings and one iron door. Each of the governors of Ransdorp, Landsmeer en Zuiderwoude kept just one key of this doors. The niche was used by them (until 1820) as strongroom to store the charters and covenants of the six villages of Waterland.