I can´t open the last door of the caves, one near the lava.... i have de key but is impossible

Could you give us some more details which door you mean exactly (level and position)?

Just bash it open. It's the entrance to an end-game area anyway, so if you're in act 1 there's some mobs there and that's it.

LordCrash: He meant the one that has a lava pool behind it.

yes, with the lava pool, just only attacking the door????

Yes, just attack the door, attacking doors is very important in this game.

Well, doors are probably heretics anyway so they deserve it.

;)

very very difficult, i pass, but a lot off mages and i died

Mages AND golems, that door was FUN.

ok, i kill all, and now....

Bash it down, though it takes forever and isn't worth it. There's nothing there for you until Act 3.