For any animal, including humans, the ability to remember where an important place is and to navigate to it efficiently are vital, as taking a wrong direction can mean finding death instead of finding home. Studies have investigated the cognitive and neurological mechanism governing these abilities, but they have focused mainly on one specific type of environment – flat surfaces extended only in the horizontal dimensions. However, the world is not flat. Every day we navigate in vertical environments, both natural (hills, mountains) and man-made (stairs, stories of a building). Therefore, it is important to understand how humans perceive, memorize and process spatial information in order to find a goal in a three-dimensional world. The vertical dimension adds a unique quality to the environment because it is parallel to the force of gravity. In fact, navigating on a tilted surface requires more effort compared to a flat plane, and this increased energy demand renders the vertical dimension perceptually and cognitively salient. Furthermore, navigation on a vertically extended surface provides a suite of multimodal sensory activations, which differ from locomotion on a horizontal surface, as a consequence of kinesthetic, proprioceptive, vestibular and visual stimuli. Therefore, vertical environments involve a different sensory experience compared to horizontal environments.Volunteer students will be recruited for a series of behavioral studies. The general procedure will consist of a goal-finding paradigm: an object will be hidden in an environment with a vertical component, and participants will have to navigate and find it. Manipulations on the environment (e.g., degree of inclination, availability of landmarks or other cues) will reveal what is the role of the vertical dimension for memory and navigation.