I rediscovered this article recently and loved all the creative answers on how a mermaid might build underwater.

This, for me, brought to mind Atlantis, the kingdom that sank into the sea. I've seen some media where Mermaid kingdoms were called Atlantis, and it's given me an idea. What if some mermaids came upon a sunken city, then added onto it?

How could a race of air-breathing mermaids retrofit Atlantis to live comfortably?

I'm assuming this city would have Ancient Greek architecture, since the story originated with Plato. I chose air breathing mermaids because I think this is an interesting engineering challenge. My big theory is that they would need to get lots of water out of different spaces to make somewhere to breathe, and somehow keep it circulating. But I'm sure there are a lot more difficulties.

  • 1
    $\begingroup$ Why do you expect there to be any air left in Atlantis? $\endgroup$
    – MichaelK
    Oct 12, 2017 at 6:18
  • $\begingroup$ Whoops that's a mistake. I meant to say water, because they would need air to breath. I'll fix that $\endgroup$ Oct 12, 2017 at 6:20
  • $\begingroup$ physics.se suggests with a big enough bubble you don't need to do anything to keep the air breathable. Unfortunately the size required means you could only spend like 10min per day in a building the size of the Parthenon $\endgroup$
    – user25818
    Oct 12, 2017 at 19:50

2 Answers 2


Used for storage, at the most

Landlubber humans lead a two-dimensional existence, being bound to the ground by gravity. Hence all of our architecture revolves around this sad fact. Our buildings are flat and sprawling. All our furniture is made to rest on the ground. And the furniture relies on us humans being glued to it by gravity.

Merfolk on the other hand lead a three-dimensional existence. If you have ever gone diving(*) you will quickly notice the difference. Gravity does not matter all of a sudden, at least not to you personally. Things may sink or float, yes, but you do not. You can "fly" independently of gravity. Moving up and down is as natural as moving left, right, forward and back.

enter image description here

Under water, you are moving in three dimensions. (Image Source)

So to merfolk, a place such as Atlantis is... well... strangely flat. You have to go all the way down to the bottom to even reach the doors to get into the buildings. Everything is as if built by bottom-dwellers. Whenever you need to go from one room to another, again: down to the floor before you can go someplace else. And all the furniture would be next to completely useless, because they all rely on gravity and a two-dimensional existence.

I think that the only buildings merfolk would find to be of any great interest to actually spend time in would be those that are tall, wide on the inside and have easy access. Like so...

enter image description here

(Image Source)

...while the rest would most likely only be used for storage, to keep stuff from being eaten or being carried away by currents.

(*) I highly recommend everyone reading this to try out diving. It is not nearly as scary as you think, quite easy, and getting an open water certificate is usually cheaper than getting a driver's licence.

  • 1
    $\begingroup$ Windows should give access to all floors of a building. Also, it is not necessary to go down to the floor to go up a level, only down to the top of the doorway. A staircase will be a diagonal path to the next floor with decorative bumps on the bottom (might keep crabs from climbing them) that you use if you aren't near the outside wall (out a window and then in). Also, smaller rooms give you less "float around" space for sleeping (like astronauts). $\endgroup$
    – ShadoCat
    Oct 12, 2017 at 17:33

They could colonize the existing sunken cities, like sea creatures colonize sunken ships, but not build anything new.

That's because of Newton's Third Law, which -- in this case -- is why merpeople can't exert much force while floating in the water: try to pick up a large rock, and it's the merman who moves, not the rock. Naturally, they can't stand on the sea floor because tails are flimsy.

OTOH, terrestrial creatures can pick up large rocks because our legs exert counterbalancing force on the Earth as we pick up the big rock.

  • $\begingroup$ Perhaps they could use their tails to manipulate the rocks, whilst using their arms to exert counterbalancing force on the earth. $\endgroup$ Oct 12, 2017 at 9:51
  • $\begingroup$ @CallumBradbury fish tails are flimsy. I just emphasized that in my answer. $\endgroup$
    – RonJohn
    Oct 12, 2017 at 13:42
  • $\begingroup$ They don't need to move large rocks, they can manage small ones. What looks like challenge to me is preparing mortar underwater. $\endgroup$
    – Alexander
    Oct 12, 2017 at 17:05
  • $\begingroup$ @Alexander hogwash. $\endgroup$
    – RonJohn
    Oct 12, 2017 at 17:10
  • $\begingroup$ @Alexander I'm not sure mortar is strictly necessary, especially if you're going for an ancient-ancient greek look. Cyclopean architecture has been used to make some pretty impressive fortifications. $\endgroup$ Jul 23, 2018 at 9:24

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .