Leaning Strata, Robert Smithson,1968

A Heap of Language, Robert Smithson,1966

Robert Smithson's article" Strata: A Geophotographic fiction" (1970-71)

Sign-- Hayden Planetarium, Robert Smithson's " The Domain of the Great Bear" (1966)

A Non-site (site-New Jersey), Robert Smithson,1967, installation

Partially Buried Woodshed, Robert Smithson, 1969 Kent State University

Asphalt Rundown (Flows series), Robert Smithson,1969,Rome

Mirror Displacements (series of nine installations), Robert Smithson,1969, Mexico

Upturned Tree, Robert Smithson,1969

The Museum of the Void, Robert Smithson,1967

Floating Island, Robert Smithson,1970(built 2005)

Sprial Jetty, Robert Smithson,1970,Utah

Sprial Jetty, Robert Smithson,1970, Utah

Amarillo Ramp, Robert Smithson, 1970, Utah

Double Negative Michael Heizer, 1969-80, New Mexico

Valley Curtain, Christo Javacheff and Jeanne Claude, 1970-72, Colorado

Running Fence, Christo Javacheff,1976, California

Lightning Field, Walter de Maria,1977, New Mexico

Belts, Richard Serra,1967

Casting, RIchard Serra,1969

Prop Pieces, Richard Serra,1969

Strike: to Roberta and Rudy, Richard Serra,1969-71

One Ton Prop (House of cards), Richard Serra, 1969

Shift, RIchard Serra, 1970-72, King City, Ontario

To Encircle Base Plate Hexagram, Right Angles Inverted, Richard Serra, 1970, the Bronx, New York

Sight Point, RIchard Serra, 1971-75, Stedelijk Museum, Amsterdam

Terminal, RIchard Serra, Boshum (Germany),1977

Twain, Richard Serra, 1974-82, St. Louis

Wright's Triangle, Richard Serra, 1976-80, Western Washington University

Berlin block for Charlie Chaplin Richard Serra, 1977, Berlin (New Gallery)

Tilted Arc, Richard Serra , 1979-80, New York

Geometric options for Title Arc: a) conical section; b) cylindrical section