Over the past decade high energy heavy ion collisions at the Relativistic Heavy Ion Collider and the Large Hadron Collider have begun to explore matter at unprecedented extremes of energy and density. Experiments at both colliders have observed signatures of a strongly coupled Quark Gluon Plasma (QGP) - a thermalized state in which quarks and gluons are the system’s relevant degrees of freedom. Among them, results from the ATLAS experiment at the Large Hadron Collider with Pb+Pb collisions have furthered our understanding of the nature of the QGP as we work towards a deeper understanding of the nature of quark and gluon interactions. In addition to the Pb+Pb collisions, ATLAS has also studied p+Pb collisions in which unexpected collective properties have been observed. Recent results from Pb+Pb and p+Pb collisions will be discussed.