Electronic Orientation Aids (EOA) usually guide visually impaired pedestrians using turn-by-turn instructions. However, several studies have demonstrated that mental representations of space seem difficult to build when turn-by-turn instructions only are provided. This is a crucial point as getting an accurate spatial representation of the surroundings can make the difference between successful and unsuccessful navigation. In this paper, we describe components of a guidance system designed to provide a better service in wearable electronic orientation aids for the visually impaired. They especially include non-visual landmarks and points of interest that are used as environmental features to improve mental spatial representations.