Had an awesome experience in Amsterdam. Walking along the street about 2 hrs in to some mushies, and the was a paving slab missing on the street. I looked down into it and it was like an looking into q vortex of space. I could see millions of stars spinning around forever with purple electric lines of light whipping around and lashing at the bigger stars. Felt like I was staring down there for an hour or so but was less than a few seconds as I was holding hands with a girl who yanked my arm as she stepped ahead of me at which point it disappeared.