The Rope

I'm sitting in a lake, floating at the surface with my family. We are near a cliff face and there is a rope hanging down from an enclosure far above. I start climbing the rope thinking how I can't think about it because of my fear of heights. I start off climbing at a decent pace, but quickly slow down. The rope starts swinging and I'm holding on for dear life, trying anything that will slow me down. I drag my legs in the water (for some reason I'm low enough again) but that doesn't work. I get desperate and just start climbing without using my legs and I'm climbing so fast I reach the room at the top of the rope. Inside there is just a bunch of stuff that looks like junk and a bookcase that has a strange frog looking object on it. I remember doing it before, so I stick my finger down the frog objects throat and a secret passage opens.

I can't remember what was behind the secret passageway.