Eros (designation 433 Eros) is a large asteroid. It's a part of the Asteroid Belt, but its orbit crosses the orbits of both Earth and Mars.
Eros is the site of Eros station, a space station that was one of the first sites of human colonization, and which by 2350 supports a population of one and a half million humans (a little more than Ceres has in visitors at any given time).
Roughly the shape of a potato, it had been much more difficult to spin up, and its surface velocity was considerably higher than Ceres' for the same internal g. The internal caverns of Eros were the birthplace of the Belt. From raw ore to smelting furnace to annealing platform and then into the spines of water haulers and gas harvesters and prospecting ships. Eros had been a port of call in the first generation of humanity’s expansion. From there, the sun itself was only a bright star among billions.
The economics of the Belt had then moved on. Ceres Station had spun up with newer docks, more industrial backing, more people. The commerce of shipping moved to Ceres, while Eros remained a center of ship manufacture and repair. On Ceres, a longer time in dock meant lost money, and the berth fee structure reflected that. On Eros, a ship might wait for weeks or months without impeding the flow of traffic. If a crew wants a place to relax, to stretch, to get away from one another for a while, Eros is the port of call. And with the lower docking fees, Eros Station found other ways to soak money from its visitors: Casinos. Brothels. Shooting galleries.
Its big docks are in five main clusters around the station. The old shipyards protruded from the asteroid, great spider webs of steel and carbon mesh studded with warning lights and sensor arrays to wave off any ships that might come in too tight.