Early in the twentieth century the curious quantum relations among conjugate variables were discovered linking Energy to Frequency and Momentum to Wavelength. In today's physics these relations allow one to reliably discern the physics topic simply from the energy scale: eV for atomic and molecular physics, MeV for nuclear physics, and GeV (and up) for High Energy Physics. In this light, nuclear physics at the hundreds of GeV scale scale would seem to epitomize the old adage, "You can't see the forest for the trees." The resolution to this apparent oxymoron is that High Energy Nuclear Physics seeks to investigate the highest possible energy density rather than the smallest size or structure. Experiments at Brookhaven National Laboratory's Relativistic Heavy Ion Collider (RHIC) have indeed revealed a new and unique phases of matter reminiscent of the first few microseconds after creation. The new phase is seen to have properties quite different from naive expectations. In this talk, I will review and interpret the exciting RHIC data and discuss the future of experiments at the forefront of energy density.