OLD COPPER CULTURE II, MN
MONKS MOUND, CAHOKIA, ILLINOIS
HOUGHTON’S PETROGLYPH
ITA LETRA, PARAGUAY
SENTINEL ROCK, VERMONT
METAL TRADE IN THE BRONZE AGE
CIRCLE CROSS CARVING, MI
MYSTERY MOUNTAIN (I), WV
STONEHENGE: DISCOVERY OF AMERICA
MYSTERY MOUNTAIN (II), WV
SWAN STONE, ILLINOIS
