&hint1=I am a 20th century structure designed by Walter Gropius&
&hint2=I feature ribbon windows and structural steel hidden by stone in monumental building projects&
&hint3=I encapsulate the machine aesthetic in architecture&
&hint4=The main building of this group has the shape of a propellor when viewed from the air&
&choices=Sunday Afternoon on the Isle of the Grande Jatte;Light Prop for an Electric Stage: Light-Space Modulator;Unique Forms of Continuity in Space;Bauhaus Stairway;Bauhaus Buildings;In the Time of Harmony&