The Lower City is one of the locations in Baldur’s Gate where most of your quests will be taking place, including the main story quests.
However, you won’t be able to get in just yet as the drawbridge is raised and Flaming Fists are guarding the entrance to Wyrm’s Rock Fortress, which you need to access.
You will need to make your way into Wyrm’s Rock Fortress before you can head to the Lower City and there are a few easy ways to do this.
Ways To Enter Wyrm’s Rock Fortress
Cross The Drawbridge
If you speak to one of the guards, you can gain entry to Wyrm’s Rock Fortress and this is also where you can encounter Gortash.
You will be denied entry at first but if you have gone through with the Investigate The Murders and/or Solve the Open Hand Temple Murders quest, you can get a Lower City Pass.
After gathering evidence, speaking to Investigator Valeria will result in him giving you the pass and you can mention you are investigating the murders to get through.
Another way would be to resort to Ability Checks to get through and depending on what is available, you can pass the Ability Check to get through.
Damaged Wall Around The Fortress
If you skipped out on investigating the murders that have been happening in the Open Hand Temple, you can always head to the side of the drawbridge.
There is a damaged fence where you can jump across or use spells to reach the lower part and this leads to a damaged part in the wall.
Going through will get you into the prison, where you can easily escape and even rescue Counsellor Florrick along the way.
Head For The Ceremony Hall From Outside
There is another path that you can take and this leads to a higher part of the fortress, which can be found by climbing up a ladder near one of the Steel Watchers.
You can get up on top of a roof and use skills such as Misty Step to get to the lower part and continue making your way to the side.
This will lead to a door that allows you to reach the ceremony where Gortash is, which begins your encounter with him.
Eventually, you can choose to attack or become allies with him, granting you free passage without having further problems with the Flaming Fists in the area.
Verdict
Gaining access to Wyrm’s Rock Fortress is necessary for you to proceed into other areas such as the Lower City and you will eventually have to meet Gortash in person.
Fighting your way through may be one of the solutions but this can be difficult and can cause you to lose opportunities along the way.
Once you have met with Gortash, you can decide to side with him for now and later change your mind if you prefer to do so.