Two Worlds:Gor Gammar
Gor Gammar is a massive Orc city the farthest down south. All around the castle are Lava Dragons. Inside are orcs all over the city with bows and strong weapons. The orcs in Gor Gammar have a lot of strength. The way to get in Gor Gammar is to go around the city and go into a Cave entrance and come out the other way into Gor Gammar. Also Inside Gor Gammar is the Fire Element needed with the Relic Frame.
You will imediatlly be swarmed by orcs, but if you are doing the quest to get the Fire Stone, then a necromancer will give you a bomb which can destroy everything in Gor Gammar instantly.
Another Way to get into the city is by equiping the Orc Camoflage armor. This will be much easier, but you don't get the experiance and/or satisfaction for blowing the city up with a massive bomb.
The Fire Stone itself is in the Centre of the City (What a surprise!). If you want to try a challange, try getting the Fire Stone without using the Camoflage or the Bomb.
To get the Bomb, you will need to speak to the Necromancer Ashmohar. He is situated quite a long way North-East, in and area just below the Drak'ar Desert. He wants you to bring him a scropion tail. When you give it to him he wants you to get rid of a group of octogons who disturb the glade that he wants to use for his research.
After this, head to the glade and he will give you the bomb. If you return to Ashmohar after you have detonated the bomb, you will find a paladin who has disposed of Ashmohar.