Hall Of Justice
At the end of Justice League, Bruce Wayne returns with Alfred and Diana to the dilapidated Wayne Manor (first seen in BvS). We still don’t know the reason for this, but moving forward it’s clear that it’s about to get a renovation. “A big round table right there,” Bruce muses in this scene, as he imagines what he’s going to do with the Manor’s grand hall. “With room for six chairs.”
In other words, Bruce is planning to transform Wayne Manor into a headquarters for the Justice League. Which classic DC fans will know as the Hall of Justice, most familiar from the Super Friends TV show. The League have also been known to gather around a big table, like King Arthur and his knights.
This is usually more commonly associated with the League’s precursor, the Justice Society, though. Seeing as the Society might not have existed in this continuity, however, it makes sense to have the earliest form of the League take inspiration from the JSA. Typically, modern iterations of the League make their base in the Watchtower, a satellite orbiting the Earth that’s also owned by Bruce Wayne.