Many environmental landmarks are available to us while navigating in familiar or unfamiliar surroundings. Landmarks can be environmental features in close proximity to the person such as shops and buildings on a street, or they can be distant features like a mountain range. We could use environmental landmarks paired with directional information and body turns while following a given route (e.g. turn left at the bank and right at the pharmacy, the mountains are on your left). You may easily get lost if good environmental landmarks are not available to you, or your skills to make use of them are poor.
Environmental landmarks are also used to create a mental representation of the environment that includes their spatial location with respect to one another, that is a "cognitive map". A cognitive map forms while individuals become familiar with a given environment. It may take some time for people to have an accurate and rich cognitive map of a surrounding. However, once formed, a cognitive map allows individuals to reach any target location from anywhere in the surrounding, even by travelling novel routes. For this reason, the use of a cognitive map is the most flexible means of navigation. In most cases, the inability to form and make use of appropriate cognitive maps is the primary reason for getting lost even in the most familiar surroundings.
Orientation can also take place in the absence of environmental landmarks, for instance by memorizing sequences of left and right turns. Distances, speed and turns are processed through a primitive orientation mechanism known as "path integration" or "dead reckoning", for which the brain tracks distance and direction while updating ones’ current location with respect to a starting point. This strategy is supported by the integration of vestibular, somatosensory, and proprioceptive information, which people may use without even being explicitly aware of. While being in an open field, you may test your "path integration" skill by walking blindfolded along the sides of a hypothetical triangle. You will be surprised to find out how close you will get to your original starting location. Despite the reliable use of processed distances and turns while navigating, this strategy can lead to errors when traveled distances and number of turns needed to be memorized increases, getting people lost.