Hypermedia makes it possible to access in a flexible and interactive way large quantities of information. Compared to intelligent tutors, hypermedia learning environments are easier to design. On the other hand, compared to textbooks, they facilitate exploration, simulation and interactive adaptation of the courseware to the user. The flexibility left to the user in hypermedia appears to pose disorientation problems. In this paper we explore how, in the context of education, the interface and especially navigational tools may be used to improve learning. We also present current research on adaptive navigational tools in educational environments: first, the information made accessible should be adapted to the level of the user, eventually unfolding only as he progresses in his learning; second, the interface should reflect the user's progression, using multilevel footprints and advice; finally, the system can offer restructuring facilities to the user for rearranging information as he explores it in order to remember it more easily.