Mercury Depot

The ship has other names, of course, depending on which world you come from, but on Earth it's called Mercury Depot because that's the planet it was orbiting when the first human noticed it.
The Depot contains the most portals in a condensed space of anywhere in the galaxy. They are carefully curated stable connections to specific endpoints in various solar systems across the galaxy. It is primarily used by the powered people of those cultures as a way to get from point A to point B in a big hurry when an ally has come under attack by a nasty problem.
As such it's also something of a waypoint. Lots of amenities, a bunch of luxury resort hotels, and a ton of nice semi-permanent headquarters for the better known agencies of the universe at large.
The Depot itself is a massive spaceship. Not a station, a ship. Important distinction, because while the portal ends remain the same, the depot travels around continually. Legend says that it's never been in the same system twice. Probably an exaggeration since if a race wasn't space ready yet, they would have to come back to set up a portal for them, but then again they could just use an outside contractor to handle it.
It looks like a space station. A lot of rounded surfaces, a tall circular shape with plenty of external docking spaces for ships. There are a few additions that stick out on the sides, but for the most part the construction has extended vertically, crafting a whole new floor as needed for space, keeping the look of the thing nice and clean and elegant and most importantly non-threatening.
If the ship is attacked, it's more than capable of defending itself. Not that anyone would be stupid enough to destroy the station outright and destabilize that many portals. What few difficulties have come are usually an incursion team aiming for a particular grouping of portals.