Vertex Citadel

Vertex citadels are citadel‑like complexes at the twelve vertices of the icosahedral rubble shield surrounding the starship Daban Urnud. From these high vantage points, they overlook the adjoining facets and mount equipment that interacts with the wider cosmos.

Appearance and construction

Each vertex is an assemblage of domes, cylinders, gridwork, antennae, and extravagant bouquets of silver parabolic horns. Five massive “knuckles” where shock pistons meet form the base of a vertex; superstructure rises above to house instruments and access ways between exterior and interior spaces. Some vertices are pressurized modules; others include through‑tunnels or exposed mechanisms.

Roles and functions (observed)

• Observatories: At least one vertex is an optical observatory. Its spherical telescope dome is split into two hemispheres that slide apart to open the instrument to space, and the dome itself functions as a large airlock that can be sealed and re‑pressurized for maintenance. Telescopes there are operated remotely over the visitors’ network, while the largest instrument has been described as actively surveying the surrounding cosmos.
• Command and operations: Another vertex is identified in‑story as a military command post, indicating a mixture of scientific and operational roles across different vertices.
• Support for major apparatus: One vertex serves primarily as a support base for the World Burner, with extensive trusswork, plumbing, and lighting; around a hundred suited personnel were seen working on the complex during a period of heightened activity.

Access and relation to the ship

• Vertex citadels sit on the joints where shock pistons converge, tying the rubble shield to the ship’s interior structure.
• Pressurized hatches within a vertex lead inward to corridors and service spaces; from a vertex, travelers can reach the despun Core regions and the rotating Orbstack.

Current understanding

Accounts assembled by avout and Sæcular observers depict the vertex citadels as key interface points between the shielded exterior and the inhabited interior of Daban Urnud. Their purposes vary by vertex—observing, commanding, or supporting hardware—and they are staffed or tended by personnel associated with the Geometers. Specific interior arrangements and control practices are reported from close observation and should be treated as in‑world testimony rather than settled fact.