is a Unitarian Universalist church in Oak Park, Illinois, and the home of the Unity Temple Unitarian Universalist Congregation. It was designed by the American architect Frank Lloyd Wright, and built between 1905 and 1908. Unity Temple is considered to be one of Wright's most important structures dating from the first decade of the twentieth century.[3] Because of its consolidation of aesthetic intent and structure through use of a single material, reinforced concrete, Unity Temple is considered by many architects to be the first modern building in the world. This idea became of central importance to the modern architects who followed Wright, such as Mies Van Der Rohe, and even the post-modernists, such as Frank Gehry.