Whether to inspire awe or push the technical limits of their medium, sculptors have long worked on a larger-than-life, even monumental scale. Iconic examples can be found all over the ancient world: colossal Olmec heads dating around 1000 B.C. in present-day Mexico, human-headed winged lions (lamassi) from the 9th century B.C. in Assyria, the pediment sculpture at the Parthenon in Athens from the 5th century B.C. and the now-fragmented monumental statue of Roman Emperor Constantine from the 4th century A.D. Imposing sculptures of human forms were made by Michelangelo in the 16th century, and then again by Auguste Rodin in the 19th century. Over the course of the last century, the diverse range of large-scale sculpture includes massive abstract forms by Henry Moore, Tony Smith and Richard Serra, monumental versions of everyday objects by Claes Oldenburg and Jeff Koons, massive feats of engineering and outdoor installation by Olafur Eliasson and Thomas Hirschhorn.