Monument 23 is sculpted from andesite and falls in the middle of the size range for confirmed colossal heads . It stands 1 @.@ 84 metres ( 6 @.@ 0 ft ) high and measures 1 @.@ 2 metres ( 3 @.@ 9 ft ) wide by 1 @.@ 56 metres ( 5 @.@ 1 ft ) deep . Like the examples from the Olmec heartland , the monument features a flat back . Lee Parsons contests John Graham 's identification of Monument 23 as a re @-@ carved colossal head ; he views the side ornaments , identified by Graham as ears , as rather the scrolled eyes of an open @-@ jawed monster gazing upwards . Countering this , James Porter has claimed that the re @-@ carving of the face of a colossal head into a niche figure is clearly evident .