I've actually noticed this in quite a few arenas throught the MK past.
Reptiles Lair-MK4/G
Soul Chamber-MkGold/3

yes, there is no door in that arenas that you mentioned it. I think they are teleported.

Why does everything have to be so realistic? It is nice to play a game that has some fantasy elements in it. Isn't it nice to break away from such norms and appreciate the game for what it is? Imagine if every video game was an identical carbon copy of each other(boring)? There are other video games that have unrealistic parts to them. The shooting games for instance....how many times can you be shot before you die? Can you really ever pick up a med kits to restore your health in real life and get back to action right away? If every game was an actual representation of the real world....it would get quiet boring.

The teleporting idea sounds good.
There is a stage like that in DOA3, the mountain stage.
It doesn't make any sense for the fighters to climb a huge mountain just to fight.
But it doesn't bug me too much anyway.

Haha! You make me laugh! It's a f*cking FIGHTING game,not a RPG game! Oh, are you realised that the fighters don't take a shower and they don't eat vegetables and fruits?!
C'mon!!...

A portal.

Actually, in the concept art, there seemed to be some stairs leading up to the Falling Cliffs...

Yeah, and if u think about it - perhaps the stairs on on the other side (the part u can't see). Then they fall away with the first part of the edge that falls, when the camera pans in to start the fight. Just trying to come up with a logical explanation

Yeah, but I was wondering, even if you win a fight in the Falling Cliffs, how'd you get down?
That would kinda suck for the winner

Who changes there clothes and buys there wardrobe?:D

they helicoptored, drove, rode Kirby, waited for Bo' to fart (which wasn't that long) and rode him, or used Johnny's huge ego as a bridge

Some stages always confused me in past MK games when trying to tie them in with the storyline.
Like fighting in the Living Forrest in MK 4 when the story did not take place in Outworld. Or the MK 1 Courtyard on Shang Tsung's island in Deception.
That's when I realized that not all stages are canon. They're just there for fun (much like some fighters in Trilogy).

oh dear lord..

What are you an idiot? Its 2004, going on two thousand fucking five. THEY USED JETPACKS!
GOD! You people.

Ok Ok I post that just for fun.
It is a fight game, does not matter how they arrive in the arena. But I think that Sindel took then to the places, flying.

it's like 'beam me up scotty' ... haha

Thats like saying how can you be killed by a Death Trap in the first round and then be back for the second round. Wait let me think...it's a game? Maybe, i dunno.

Cyrax took them up with the hellicopter that he keeps in his head... DUH