This is an evocative map of the City of Galastanen.
It’s vaguely resemblant of M.C. Escher early works.
Things have a reason. Often the reason is given by the reader.
Put it in your campaign.
Put it in all your campaigns.
Stepping through the Lion Gate brings you to Galastanen.
Out of the gate lie many worlds.
Stepping out of the Lion Gate, going home is mostly guaranteed.
Unless you’re following someone else.
Because Galastanen exists in a seam of sorts.
It’s where all the universes were folded and quilted.
If such a concept could be called “where”.
Ignore the incoherent hydrography: Galastanen does not care for your Euclidean space. Water gets there from a mountaintop glacier in another world.