Interior illumination with floor-recessed luminaires achieves a particularly high level of attention. The presence of light sources on the floor as well as the direction of light from bottom to top are unusual and therefore particularly striking. Floor-recessed luminaires also assume directive or informational lighting tasks, e.g. by marking routes or highlighting entrances. Placed close to the wall, floor-recessed luminaires create impressive grazing light. For long-lasting operation, floor-recessed luminaires with an IP67 protection rating are dust-tight and protected against the consequences of temporary immersion.