Is it Sirocco Caverns?

This is a small list of what I have found are S-Tier for leveling in S2:


Sirocco Caverns
Ghoa Ruins
Deserted Underpass
Belfry Zakara

Take note, however, these are the best for leveling, not necessarily the safest in HC (poison can be dangerous).

Ok, thanks for replying, but my question still stands, which is safest dungeon to boost a low level in hardcore torment?

Domhainne tunnel loop?
Clear first area in loop / reset dungeon

Sirocco is my favorite, if you get a cursed chest it usually bugs and you can 1 shot the packs as they spawn, 1-50 usually takes like 3 runs