Board Thread:Questions and Answers/@comment-24576355-20140221215318/@comment-13413401-20140222005810

Lol. Thats from the Dimensional_Doors mod: http://tekkitlite.wikia.com/wiki/Category:Dimensional_Doors

You went through a portal into a dimesnional dungeon. Since you died in the dugeon, you were teleported to Limbo: http://tekkitlite.wikia.com/wiki/Limbo

There are multiple ways to get out. If you want to do it the legit way, then look for fabric of reality and step on it. Otherwise, if you enabled cheats when you created the world, type in /tpx 0 in the chat box. If you didn't enable cheats, you could use NEI to get a nether portal block and go to the nether, then back to the overworld.