Three part lecture on metamaterials. Metamaterials are expected to open a gateway to unprecedented electromagnetic properties and functionality unattainable from naturally occurring materials, thus enabling a family of new “meta-devices”. In these three lectures, we review this new emerging field and significant progress in developing metamaterials. Specifically, we describe recently demonstrated artificial magnetism at high frequencies, including the visible part of the spectrum, negative-index in the optical range, and promising approaches along with challenges in realizing optical cloaking. The new paradigm of engineering space for light with transformation optics will be also discussed.