The nucleus at the center of Nod is a tower that stretches into a black sky with no visible summit. This pillar is the heart of the Domain, and depending on who you ask it is either nemo's dwelling or Nemo itself. The walls are made of a silver-veined black marble-like material, impervious to damage. Light near the stone produces a faint vapour that the surface seems to absorb.
The tower is wider at its base where it meets Lake Enoch below, composed of geometric protrusions, great blocks and polyhedra that create the impression of the rocks at the base of a lighthouse but more ordered. Higher up, the walls bear reliefs depicting enormous sea creatures locked in combat with equally titanic and only vaguely humanoid entities. The reliefs grow smaller and more detailed the further up one looks, and are the subject of study for Turonomers, individuals who document these images through telescopes and aerial expeditions. There is general agreement that the tower is a sort of living record, with the base depicting the earliest events and progressing forward up its height. Interpretation is difficult at best, and no expedition or apparatus has been able to peer high enough to observe anything close to recorded human history.
There is one doorway into the tower, reached by crossing a long stone bridge across Lake Enoch. This door has not opened in living memory. The last recorded instance was 1,200 years ago, during the Purge of the Third Council.