&hint1=I am located in northern Arizona&
&hint2=I have been built only using the earth's matter&
&hint3=I am an observatory&
&hint4=I lay in the crater of a dormant volcano&
&choices=Untitled, from the Arbol de la Vida;The Lightning Field;Solar Rotary: Sundial;The Shrine of Democracy;Roden Crater Project;Itiba Cahubab (Old Mother Blood)&
&answer=Roden Crater Project&
&search=Roden Crater Turrell&
&title=Roden Crater Project&
&artist=James Turrell&
&medium=Cinder cone volcano&
&date=begun 1974&
&location=San Francisco Peaks, Arizona&
&dimensions=Height 54', diameter 800'&