Synopsis This first monograph of the series is on the famous iron pillar located at Mehrauli village on the outskirts of Delhi, which has been an object of perennial interest and curiosity for lay-persons as well as scientists. It remained an enigma for centuries mainly on two counts. First relates to the technology by which a metallic object of such a large size and mass could be fashioned so many centuries ago, and the second had to do with its phenomenal corrosion-resistance despite exposure to sun, rain and wind for so long. The Rustless Wonder : A Study of the Iron Pillar at Delhi written by Professor T.R. Anantharaman, an eminent metallurgist, documents every aspect of this technological marvel. The author has gone through and summarised all important studies and researches done on the pillar during the last century and half. He shows how scholarly and scientific studies have shorn the iron pillar of practically all elements of bafflement, mystery and incredulity that have surrounded this ancient monument all along. He has also pointed out a few gaps to be filled : like the pillar's original location and its whereabouts for some six centuries before it was installed at Mehrauli. This study can undoubtedly be termed as the most comprehensive thus far on the famous pillar.