Who created heaven and hell? I'm wondering if heaven and hell was created or it always existed.

If it was created obviously God created it right? Because He is the only one capable of creating something like that. If so why make a torture chamber for you "children" if they disobey you. Even most human parents won't do something like that to their children no matter how bad they become. 

But if it always existed along with God, then he did not create everything. Maybe there more things that have always existed that we don't know yet. 

What is the truth according to the Bible?
I think almost all branches of Christianity* agree that both heaven and hell are places specifically created by God. The justification for this is pretty simple: all things outside the being of God himself were created by God. There are no other eternally existing beings, things or places, and all the extant beings, things and places are explicitly identified as having been created by God:


  Colossians 1:16 (ESV)
  16&nbsp; For by him all things were created, in heaven and on earth, visible and invisible, whether thrones or dominions or rulers or authorities—all things were created through him and for him.


The exact meaning and scope of each of these items is sometimes debated, but it's generally agreed that this covers everything. Including heaven and hell.

In the case of heaven in particular we have another indication that it is a place created by God:


  John 14:3 (ESV)
  3&nbsp; And if I go and prepare a place for you, I will come again and will take you to myself, that where I am you may be also.


Likewise for hell we have an indication that it is a place prepared for a purpose:


  Matthew 25:41 (ESV)
  41&nbsp; “Then he will say to those on his left, ‘Depart from me, you cursed, into the eternal fire prepared for the devil and his angels.


TL;DR: God created heaven and hell.

* The exceptions are of course a couple sects that don't believe hell even exists and a couple that postulate about it being a sort of less-than-fully-real place not created as hell per-se but that becomes that through acts of either man or the devil.