If stuck trying to find the Areelu Lab...

[SmoothMoovGreg]

You need to progress your mythic quests in Pulura Falls if Angelic. Progressing a Spring Run Dry quest opened the location on the map to investigate for me.

[Janthis]

If you're on the Azata path, you just get teleported there.

[Glyph]

All the mythic quests lead there, one way or the other. Most wouldn't even know it existed until you get trapped in it.

[pete3great]

As others have said, just progressing the game on any path will get you to Areelu's lab. What's interesting is that, IIRC, it's Pulura Falls you can't get to if you're on the wrong path (until later in the game, that is. Angels and Tricksters both can get there in act 3 IIRC again).