From the outside, Richard Serra's Cor-Ten-steel masterpiece "Joe" appears to list a bit to one side, like a stylish woman's hat or the prow of a ship. The sculpture is the vibrant stroke of burnished orange that glows next to the concrete Ando building and the gray-graveled ground. Step inside, and the walls teeter over you and the spiral passageway appears to contract and expand. In a certain light, they glow like desert-canyon walls. 'Round you go, touching the steel, which turns surprisingly, sensuously warm in some places. The walk can produce distressing sensations of disequilibrium -- until the center of the spiral is reached. Shadows draw lines across the inner walls, across the ground, as if they have a weight of their own. The sculpture frames the sky in a surprising way, given that you're in the middle of a city. Serra transforms space from closed to open, from anchored to released.