Intergalactic Gate

Pocket megastructures used by multiple factions for transportation between galaxies. As intergalactic travel is very difficult, most civilian ships are not capable of doing it. However, they can use these gates. Intergalactic gates teleport ships to any other intergalactic gate, they do not come in pairs. While they must use a lot of power, because they are a pocket megastructure, they cannot be turned off, so any faction can use any other factions Intergalactic Gates.
As they must be able to fit almost any starship, Intergalactic Gates are immense. The gate itself is often between 30-100 km in radius. This figure does not include the various support systems which make up most of the mass of the structure. This way, Intergalactic Gates can easily achieve over 200 km width and much larger in lengthIntergalactic gates are a conduit through the very fabric of reality itself so they require extremely advanced technology to construct. They cannot be turned off because this would cause the fabric of space to react violently and possibly turn into a black hole. The gravitational wave disturbance would destroy everything in the same system, including any star which results in the destruction of the entire star system. This technology is very impractical to weaponize as a warhead, but might be used as a scorched earth policy weapon. They have never been used this way in history before.
As such, they are constantly maintained and monitored by every faction that owns them. They can vary slightly between factions though. Hyperion Federation ones have a 40 km radius, large enough to fit a star annihilator, and are far bigger than one. It would not be able to fit anything larger though, so motherships and Planetcraft would not be able to enter.