Create an isometric drawing of a surreal architectural structure featuring a winding staircase that loops back on itself. The staircase should be made of smooth stone and supported by sleek, modern columns. Replace the traditional house element with a geometric, minimalist cube structure, with large glass panels allowing for an open view of the interior. Add a gentle waterfall cascading from one level to another, flowing into a small pond at the base. The color scheme should incorporate soft pastels and clean lines, enhancing the overall serene atmosphere.