An achiral fixed bent-core nematic liquid crystal in an antiparallel aligned planar device is observed to form three distinct domains. Regions are observed which are achiral planar, as well as domains displaying both positive and negative chirality that are stable over a significant temperature interval. In such a device the presence of spontaneous positive and negatively twisted domains is highly unusual. By studying the electro-optics of the device relevant director structures are inferred, and it is additionally found that a sufficiently large applied electric field will drive the chiral domains into the achiral state.