Microphotoluminescence studies reveal strong and narrow lines of similar to1-meV minimal width in GaN/AlxGa1-xN quantum well (QW) structures having inversion domains (IDs). These narrow lines coexist in the spectra with broad (10-15 meV) peaks. The features of both kinds are characteristic for intersections of the IDs with QWs, which provide either three- or one-dimensional carrier confinement, depending on both the ID diameter and well width.