How do I get here?

[Zemoj 0]

I haven't beaten the gym yet.

[Zemoj 0]

Also, what are the pillars that turn from blue to red for?
I've been turning all of them I find to red.

[Khayoz 0]

When you turn the pillars all to red, you will unlock the Bysbyxion Grotto. Remember that strange computer thing somewhere in the middle, and the locked door? That would now be open, and it gives you access to many areas including the one you circled.

[Zemoj 0]

I already activated the computer thing, and it said unlock complete, or something like that, and the door opened, I already beat fern at the gym.
I also can't find any more pillars.

[Zemoj 0]

Alright I found the last of the pillars, and the door opened, I'm at the grotto now, anything worth getting to help me fight Aya or what ever her name is?

[Noivy 4]

...It's best if you find out for yourself. I know there's a ghastly about, but getting to it is a very scary process if you don't know what to expect.

[Lunaethetic 0]

Hugging isn't an option.

[Khayoz 0]

There is an interesting event involving a Garbodor in there. Plus if you have a certain item from mining rocks you can catch a rare Pokemon in one of the rooms, too.

[Ussi 0]

The Dawn stone is in here. That's all you need to know.

[Zemoj 0]

I got spirit tomb, and the dawn stone.