When formulating route instructions people refer to salient objects along the route (e.g. go right at the church, take a left turn at the big intersection). These objects are called landmarks and allow the observer to locate himself and to point out directions. They help building an internal representation of an environment, understanding the area and improving the ability to anticipate further actions. Knowing that many people experience difficulties while navigating through buildings and having the different advantages in mind that they offer, it is strange that so little research has been conducted concerning the use of landmarks indoors (i.e. buildings). On the one hand, this research project focusses on the identification of landmarks with the help of thinking aloud protocols, eye tracking measures ... On the other hand, it is examined how these powerful navigation aids can be used in indoor routing algorithms and wayfinding applications.