The Sim
Our home is the Milky Way Galaxy. Between two arms, directly left of the locally known space, a deep space exploration team found an ancient precursor station.

This station turned out to be a mass driver, opening transport to other galaxies within the Virgo Super Cluster.

The Virgo Super Cluster has approximately 4,000 galaxies within it.
An example of some:

The station we found was unpowered, but through Federation ingenuity, we were able to get the singularity up and running again.