Porto: a lesson in stairs (Alvaro Siza). For whatever reason, stairs have always fascinated me. Beyond their communicative power and symbolism (Image 1 below), their beauty, craftsmanship and spatial qualities mark a building in a variety of ways. It seems part of human destiny to defy gravity and erect tall structures—in fact humans have worked toward the idea of a sky scraper since the pyramids of the ancient world, and, more recently the 13^th century towers in the Tuscan town of San Gimignano. Vertical circulation systems, primarily through stairs and ramps, have been integral to this cultural vision of building vertically.