There are two separate sources of gravity competing for control of the city of Hyperboleon. These operate perpendicularly to one another, drawing objects towards two separate grounds whose horizons meet at a right angle.
Every person or object in Hyperboleon only experiences one such gravitational pull at a time. Residents differentiate them into two polarities, positive and negative, though these do not exist antiparallel to one another as the electromagnetic forces do. Moreover, every configuration of matter is monopolar: when positive and negative raindrops collide in midair, their subsequent droplets continue downward along their original verticalities.
Because of this bifurcation, Hyperboleon may seem at first to be two separate cities which, though geographically overlapping, are fundamentally incompatible. Indeed, the Positive District only uses stone quarried from positive earth, and the Negative District’s wood is carved from timber rooted in negative soil. The vast majority of architecture relies entirely on raw materials extracted from a single domain.
Nonetheless, Hyperboleon is an integrated city, for its inhabitants have always been fascinated with one another. Residents of the two halves scale each other's roads by numerous conveyances, from escalators to gondolas to ropes. Elevators commute alongside automobiles in each morning’s rush hour traffic. Oppositely-charged citizens purchase chandeliers from one another, as well as candles, and adorn their walls with light fixtures from the other half.
Indeed, their cultures have interwoven, in spite of their compositional differences. Sometimes, opposites even fall in love.
The region of the city that has formed around the conjunction of its two earths is known as the Married District, and the reason for this is as one might expect: it belongs primarily to those who have joined together in matrimony in spite of their opposing polarities. This is the neighborhood where architectural design is most bold, for the buildings within are constructed using materials from both sides, allowing both downward forces to be integrated into their structural design. Deceptive buttresses connect walls to empty space, and carefully-arched stairwells rise in both directions.
On top of all this, much care is taken to ensure that the district’s bedrooms are built in such a manner that couples can easily share a bed. This, above all else, is sacred in Hyperboleon, for one important reason: the act of sexual union with a person of opposite charge is the only known means by which one's own polarity can be reversed.