Stumbled across this, probably good that I didn't know about it while I lived there...
Link: The Atlantis Bookshop
On this side of the world there's always
Link: https://en.wikipedia.org/wiki/Weiser_Antiquarian_Books
Frankly there's nothing better than a used bookstore or old curiosity shop, and to find a bookstore that specializes in my more esoteric/preposterous beliefs and reading is - well, I'd be there far too much I'm sure.
There are plenty more, but I'll let you discover them on your own.