Santa Fe is famous in part for a particular architectural style, an adobe (mudbrick) look that came to be called Pueblo Revival. This aesthetic combines elements of indigenous pueblo architecture and the New Mexico's old Spanish missions, resulting in mostly low, brown buildings with smooth edges. Buildings in the city's historical districts in particular have to follow a number of design guidelines so that they fit this desired look; deviating from those aesthetics can stir up a lot of controversy. But this adherence to a single style hasn't always been the norm -- for a time, there was actually a powerful push to "Americanize" the city's built environment. Then, over a century ago, a group of preservationists laid out a vision for the look and feel of Santa Fe architecture, and in the process changed the city forever.