The World Wide Web, today's largest and most important online information infrastructure, does not support 3D content and, although various approaches have been proposed, there is still no clear design methodology for user interfaces that tightly integrate hypertext and interactive 3D graphics. This paper presents a novel strategy for accessing information spaces, where hypertext and 3D graphics data are simultaneously available and interlinked. We introduce a Dual-Mode User Interface that has two modes between which a user can switch anytime: the driven by simple hypertext-based interactions "hypertext mode", where a 3D scene is embedded in hypertext and the more immersive "3D mode", which immerses the hypertextual annotations into the 3D scene. A user study is presented, which characterizes the interface in terms of its efficiency and usability.