The paper reports room temperature quantum emission from hexagonal boron nitride (hBN) nanoflakes, demonstrating the highest brightness, narrow line width, absolute photo-stability, short excited state lifetime, and high quantum efficiency in the visible spectrum. The single-photon emitter is identified as an antisite nitrogen vacancy defect, which is present in both single and multi-layer hBN. The findings highlight the potential of van der Waals crystals, particularly hBN, for applications in nanophotonics, optoelectronics, and quantum information processing. The study includes detailed characterization of the defect's photophysical properties, such as polarization, stability, and quantum efficiency, and confirms the defect's role through density functional theory modeling.The paper reports room temperature quantum emission from hexagonal boron nitride (hBN) nanoflakes, demonstrating the highest brightness, narrow line width, absolute photo-stability, short excited state lifetime, and high quantum efficiency in the visible spectrum. The single-photon emitter is identified as an antisite nitrogen vacancy defect, which is present in both single and multi-layer hBN. The findings highlight the potential of van der Waals crystals, particularly hBN, for applications in nanophotonics, optoelectronics, and quantum information processing. The study includes detailed characterization of the defect's photophysical properties, such as polarization, stability, and quantum efficiency, and confirms the defect's role through density functional theory modeling.