Stanisław Lem's gardens full of experiments

This guide walks you through Kraków's science garden named for Stanisław Lem, the science-fiction writer who imagined artificial minds and alien worlds decades before anyone built them, without ever touching a computer himself. It traces why a park built entirely for hands-on wonder went up in Nowa Huta, a district the postwar government planned around factories with no room for anything playful. Along the way you'll meet a glycerin block the size of a filing cabinet that splits sunlight into a walk-through rainbow, and a giant kaleidoscope built at a precise sixty-degree angle. Listen for the gong nearby, and try striking it soft rather than hard.