The 16th Avenue Tiled Steps, perhaps the world’s longest mosaic staircase (163 steps, 82′ high), was conceived and fabricated by Irish ceramicist Aileen Barr and San Francisco mosaic artist Colette Crutcher. Over 2,000 handmade tiles and 75,000 fragments of tile, mirror and stained glass went into the finished piece, located at 16th Ave. and Moraga in San Francisco.