1 Iki Piki: Where do we find this Vantablack Market?
2 Bar patron: Go down the Street of Shady Bars, turn left into the Street of Shadier Bars, then right into the Street of Shadiest Bars.
3 Bar patron: It’s the one right at the end. Absorbs all the light that enters. Looks like a hole in reality.
4 Bar patron: It’s a rough place though. Be careful.
4 Serron: No problem. We've created actual holes in reality.

I was almost going to say turn left and then turn left again, but that might imply that there's a shorter way to get there by going around the block in the other direction, thus completely avoiding the Street of Shadier Bars.

Which is a tourist attraction and really not to be missed.

Oh, and yes, I did think about how Quercus managed to get through that door. And then decided to let him do it anyway.