How do I get to the sewers?

At nameless path I mostly get lvl 11 items, but I am lvl 9, so the items are useless for now.
So I hope the sewers are more adequate. It is no problem to kill stuff btw, I just want to find new items that I can use.
I knocked on every door in the city - no sewers.

— edit — solved.

Well to go to the sewers you must have the quest to do It.

If you have the quest, you must return in the beach in the begining of the game, there is a waterfall, if your getting close a cinematic would start, and a way would be reveal.

You need to explore sacrament a little more… Speak to the prisoners that are locked up in caged wagons.