The entrance to the subterranean system of chambers is located on the shorter, northern side. A passage with a slope of 23°30′ leads down into the ground. It was originally 20.75 metres long, but due to a collapse it is now only 16.3 metres long. After this descent, the passage continues on the horizontal. This portion forms a small chamber with a length of 2.67 metres and a height of 2 metres. After this chamber, three portcullis stones are still anchored in the ceiling. At this point the passage is 1.1 metres wide and its height decreases to 1.27 metres. The walls and ceiling are clad in granite. After the portcullis stones, the height of the passage increases again, but the floor is very uneven, since it was no longer plastered. After a further reduction of height to 1.2 metres and a total length of 19.46 metres, the horizontal passage finally reaches the ante-chamber.
The ante-chamber has an east–west length of 8.31 metres, a width of 3.05 metres and a height of 5.55 metres. It has a pointed roof made of granite. A 1.2 m-high (3.9 ft), 1.11 m-wide (3.6 ft) and 1.54 m-long (5.1 ft) passage with a slope of 10°30′ extends from its western end, leading to the burial chamber. This is 7.79 metres long, 3.85 metres wide and 4.9 metres high. It has a pointed granite roof, with a ceiling shaped like a barrel vault. Only fragments remain of the sarcophagus, which was probably made of greywacke or basalt. The ante-chamber and burial chamber were both clad with granite, but it was not smoothed or polished.
Another passage leads south from the southeast corner of the ante-chamber. It is 10.62 metres long, 1.14 metres wide and between 2.1 and 2.3 metres high. On its east side there are four small niches and there is another one on the west side, immediately opposite the southernmost of the eastern niches. The eastern niches are between 2.1 and 2.27 metres long, barely 0.8 metres wide and 1.4 metres high, the western niche is 2.65 metres long and 1.16 metres wide.