Surveying Anderson's complete canon, we see:
a version of Atlantis;
the legend of Ys;
the Fall of the Roman Empire;
the Viking period in myth and history;
aliens, mermen and men in the fourteenth century;
time travelers and immortals in diverse periods;
fantasy and mystery in the twentieth century;
many alternative futures;
human and cosmic destinies;
many alternative timelines;
different kinds of universes;
a place between the universes and timelines.
We are in that place when we read Anderson's works - guests in the Old Phoenix Inn, drinking with van Rijn and Holger Danske.