Neurons in sensory areas are tuned to various input features, and tuning properties reveal essential aspects of the computation performed by the neuronal population. In the post-subiculum (PoSub), neurons are modulated by the animal’s head-direction (HD), and most pyramidal neurons are fine tuned to a specific direction. Other cell types, especially fast-spiking neurons, are less specifically tuned but are generally still modulated by HD. By recording from ensembles of neurons in the PoSub in freely moving mice with linear silicon probes, making it possible to determine precise anatomical location of each neuron, we show that there exists a population of neurons that show virtually no modulation by HD. They formed a separate phenotype as the distribution of HD modulation was not a continuum but was rather bimodal. These neurons represented about 5-10% of the total number of neurons. They did not show any specific anatomical distribution and were recorded in proximity of HD cells. Action potential waveforms and intrinsic dynamical properties indicate they are putative pyramidal neurons, although there is a possibility that a subclass of inhibitory neurons show similar properties. One key difference was that these neurons were more modulated by theta than HD cells. These findings reveal the existence of neurons functionally disconnected from the brain structure they belong to.