Understanding and ultimately controlling emergent quantum phenomena requires probing light–matter interactions and many-body dynamics at their intrinsic spatial, temporal, and energy scales. Pushing the frontiers of quantum materials research toward nanometer–femtosecond–terahertz resolution demands new experimental capabilities that integrate coherent THz spectroscopy, near-field nano-optics, and scanning-probe techniques under extreme conditions of cryogenic temperatures and high magnetic fields. In this colloquium, I will discuss our recent advances in THz near-field imaging and nano-spectroscopy that open new windows into correlated and topological quantum matter. I will highlight how nanoscale electrodynamic imaging reveals magnetic-field-driven colossal magnetoresistive switching and resolves layer-dependent chiral edge responses. Finally, I will present our progress and outlook toward deep-subwavelength THz coherent control of gate-tunable atomic-layer devices, opening opportunities to visualize, manipulate, and ultimately engineer electronic dynamics at their intrinsic scales.