Dungeons
There are eight dungeons with at least four paths each, but no one really counts story mode, so figure 3 paths each…in addition to Fractals.
The dungeons are layered to around 1 every 10 levels starting at level 30 with explorable mode opening on the 5.
So at level 30 you can do Ascalonian Catacombs story mode and at level 35 you can do Ascalonian Catacombs explorable modes (but I’d way till you’re higher to try it in explorable mode).
At level 40 you can do Caudecaus’ Manor and at 45 you can do explorable mode of the dungeon.
It goes like that all the way to level 80.
Fractals generally take longer to run than most dungeon paths. How much time depends on what level fractals you’re running as do the rewards. But if you’re playing this game just for rewards, you’ll probably end up having a hard time.
The hardest dungeons outside of the fractals are Arah, all four paths, and the Twlight Arbor Aetherpath all of which are level 80.
Just a suggestion, but there is a dungeon dedicated area here. Lots of info there.