The interior of Coriopolis is arranged along the cylinder’s 80-kilometer length as a gradient from dense urban development at the northern end to managed wilderness at the southern end. Because the inhabited surface wraps around the full inner circumference of the 20-kilometer-diameter cylinder, the landscape curves upward in every direction, meeting overhead at the opposite side.

Northern cityscape#

The northern end of the cylinder contains the primary urban area. Buildings are constructed directly on the inner surface and rise toward the cylinder’s axis, where effective gravity decreases. The tallest structures reach heights at which the reduced gravity is noticeable to occupants. Overhead, holographic emitters on the inner face of the gap between Coriopolis’s two cylinder sections project a simulated sky.

The cityscape includes residential towers, commercial districts, public squares, and parks. Street layouts follow the cylinder’s curvature, so long sightlines curve gently upward rather than receding to a horizon. Transit systems run both along the cylinder’s length and around its circumference.

Transition zone#

Between the urban north and the preserve south, the built environment thins over a stretch of several kilometers. Building density decreases, structures give way to low-density housing interspersed with cultivated green space, and engineered terrain gradually replaces paved surfaces. The transition is continuous rather than sharply bounded.

Southern nature preserve#

The southern portion of the cylinder is a managed ecosystem containing forests, grasslands, rivers, and lakes. The terrain is sculpted to create elevation changes, valleys, and ridgelines despite the underlying cylindrical geometry. Scimitar Falls, one of the habitat’s most recognizable landmarks, is located within the preserve.

The preserve supports a variety of flora and fauna selected and adapted for conditions inside the habitat. Birds in particular exploit the cylinder’s internal air currents — including Coriolis-deflected wind patterns — for sustained, low-effort flight. The ecosystem is largely self-sustaining, with nutrient cycling and water management systems integrated into the cylinder’s infrastructure.

Viewing geometry#

The curved interior surface means that an observer standing anywhere in Coriopolis can look up and see the opposite side of the cylinder overhead. From the cityscape, the nature preserve is visible as a band of green arcing across the sky; from the preserve, the city’s lights are overhead. This effect is a defining visual characteristic of life inside a gyrealm.