Landmarks, by their pure existence, structure environments. They form cognitive anchors, markers, or reference points
for orientation
, wayfinding
and communication. They appear in our sketches, in descriptions of meeting points or routes, and as the remarkable objects of an environment in tourist brochures. With all their significance for spatial cognition
and communication, landmarks pose a major challenge for artificial intelligence and human-computer interaction. So far, research aiming for intelligent interaction design has suffered from a lack of understanding and formal modelling of landmarks. Here we will clarify our words’ meaning and draw some boundaries of our discussion, in preparation for integrating landmarks in artificial intelligence applications.