Where are stored the Multiverse's generated worlds? Can I export a world without replacing other ones?

Hi!
(Bad English, beware)

I'm trying to find where are stored all of the Multiverse's generated worlds. I wonder if I could use it to export a world using Multiverse so I can export it without deleting other existing ones.

Thank you in advance!

Lukaka.

Yeah, but I couldn't import a new world by the worlds page. I wonder if there is a command or something like this for that manipulation.

I did it! I created a world with Multiverse Core, stopped the server, then went to Worlds and imported it to that one world, and back in the server, it worked!

Thanks for your help.