With a cascading skylight roof that arcs over each terraced floor plate, the Van Andel Institute in Grand Rapids, Michigan, visually evokes the rapids of the nearby Grand River while housing a cutting-edge cancer research institute. Responding to an irregularly shaped, sloped site in an urban center, Rafael Viñoly Architects designed for the private institute, founded in 1997, a flexible, phased-growth facility that would encourage researcher interaction and adapt to fit the changing needs of the research program.