Island in the Sky

Where is this place? A tall rock in the sky. It's a long way down.

Four odd short posts, and a small building with a mountain behind it. Inside the building two bookshelves built into the walls, and a lever to control the blinds. Not much to do in here but read books, and they're full of philosophic stuff. Can't make head nor tail of it. So, back outside.

Hmmm. The posts have handprints on them. Looks like an invitation to me. I touch one and it slides open, and there's a linking book inside. I wonder if the others work the same, so I touch them and get all four open. Oh, boy, four places to go!

I pick one at random and link out.