High-mass stars live short but intense lives and their deaths, in numerous ways, affect generations of stars to come. Therefore, understanding how massive stars are born is a fundamental task in modern astrophysics. Despite its importance, there is no consensus on how massive stars are formed and discriminating between different theories, such as Core Accretion and Competitive Accretion, is a critical topic in current research. This project analyzed near-infrared images from the Hubble Space Telescope (HST), alongside ancillary data from ATCA, ALMA and the VLA, of the high-mass protostar IRAS16562-3959. This region is 1.7 kpc away with a bolometric luminosity of 70,000 Lsun and an estimated protostellar mass of 15 Msun. First, the geometry of the outflow cavities from the protostar were characterized, including the opening angle and symmetry of the flow. Excitation conditions in the outflow were assessed by consideration of [Fe II] and H recombination line emission. Second, the protocluster environment around the massive protostar, especially in its low extinction near-facing outflow cavity, was characterized by searching for lower-mass protostars. A protostellar number density of about 5 stars per pc3 was estimated within a scale of ~0.1 pc from the massive protostar. This estimate was compared to theoretical predictions from a simulation of massive star formation via competitive accretion, which are > 50 stars per pc3. The lack of the presence of a significant cluster of lower-mass protostars and the symmetric geometry of the outflow structure indicate that IRAS16562-3959 is forming via Core Accretion, with relatively little fragmentation occurring in the region.