Vidiia

Vidiia is a planet in a system in the Delta Quadrant and homeworld to the Vidiians and capital of the Vidiian Sodality. (Star Trek: Voyager; Star Trek: The Expedition) Starfleet have established the Outpost Delta space station in Vidiia's orbit at the Vidiians' request.

Vidiian Capital
The Vidiian Capital was a large, ancient, sprawling, home to the Vidiian Presidential Palace, Vidiian Main Library and Vidiian High Courthouse. It was also the seat of power for the Vidiian Sodality. (Star Trek: The Expedition: "Sodality", "Brink of War")

After the phage hit the Vidiians, their resources went into curing the disease, and the capital, as with most cities, fell into a state of disrepair. With the phage cured in 2375, the Vidiians could start rebuilding. Various areas of the capital were still undergoing repair even as late as 2384. (Star Trek: The Expedition: "Sodality", "Brink of War")

The capital was built on top of an earlier version of the city, the old city still somewhat visible in the Vidiian Sewers. (Star Trek: The Expedition: "Sodality")

Vidiian High Courthouse
The Vidiian High Courthouse remained in limited use throughout the phage, although its disrepair continued during that time. In 2384, Keyvon and the Alliance used the courthouse to try Jeremy Aster for murder and various other charges. (Star Trek: The Expedition: "Brink of War")

Vidiian Main Library
The Vidiian Main Library housed various computer terminals linked with government departments throughout the Sodality. In 2384, USS Discovery (NCC-81316) first officer Commander Zee Kendral used the main library's terminals to attempt to find out more information about the mysterious Project 47. (Star Trek: The Expedition: "Sodality")

Vidiian Presidential Palace
Once used as a royal palace, in modern times, the Vidiian Presidential Palace housed the elected president of the Vidiian Sodality, and a large plaza stood outside the palace's front. Even as late as 2384, the palace was under reconstruction after its neglect during the phage. Discovery captain Adrian Jacobs met the president there in the same year to discuss the terrorist attack on the Discovery's away team. (Star Trek: The Expedition: "Sodality")

Vidiian Sewers
The old city -- millenia older than the capital city itself -- became part of the Vidiian Sewer System. The sewer system was not easily accessible from the surface, and, once inside, it was a maze of various wide and narrow corridors, hidden rooms, and old, derelict buildings. (Star Trek: The Expedition: "Sodality")