Transportation are trams that travel at a light speed between each city that has a hub like airports in each city. The hub to enter Atlantis is walking distance from the Asgard.
Atlantis is a Kingdom that's further out in the ocean, but main entrance will be facing Asgard. There is a small community for land breathers to live within Atlantis. There's hospital, public school, and Royal Guards, anyone held by the Royal Guards will have to face the judgment of King Aren Curry.
Atlantis Kingdom under the sea. Hotel for land lovers (bars, stores, restaurant, sea adventures)