Both of the suggestions below would be like Najena. They are not outdoor dungeons like CT or Unrest.
From level 30-40 I did Crystal Caverns on my Monk. You can do the Orcs in your low 30s, and then graduate to spiders/geos. Since you need to use Root instead of Harmony to split mobs you might have some problems though, especially with the Orc Shamans. My Monk was also more twinked than your Ranger.
Tower of Frozen Shadow is great for leveling from your 30s all the way to 50. You should be able to do floor 1 at level 30. It's probably better to start there in your upper 30s though. I started on floor 3 at level 40 on my Monk. Floor 2 has spell casters, so you'd need to test out how often they end up landing spells on you if you wanted to level there a bit earlier in your 30s. You would probably need some resistance gear. You can do Floor 3 for a while in your 40s. Then go up to Floor 6 in your upper 40s. Floor 4 and 5 aren't great for leveling.
Tower of Frozen Shadow is difficult to get your corpse in. The keys to each floor do not appear in your inventory when you die like the Sebilis Key. You will need somebody with keys to help you get your corpse, or get a Necromancer to summon your corpse to the entrance.
If you do choose Tower of Frozen Shadow, I recommend having a
https://wiki.project1999.com/Leather...aider_Skullcap so you can immediately escape in an emergency. You could probably do the Leatherfoot Raider Skullcap quest yourself since you should have good faction with halflings as a ranger.
https://wiki.project1999.com/Vial_of_Swirling_Smoke works too, but Leatherfoot Raider Skullcap will save you more money over time, as the recharge cost is cheaper than buying a new Vial of Swirling Smoke.