In this paper, we argue that web applications are a particular kind of hypermedia applications and show how to model their navigational structure. We motivate our paper discussing the most important problems in the design of complex Web applications. We argue that if we need to design applications combining hypermedia navigation with complex transactional behaviors (as in E-commerce systems), we need a systematic development approach. We next present the main ideas underlying the Object-Oriented Hypermedia Design Method (OOHDM). We show that Web applications are built as views of conceptual models. We next present the abstraction primitives we use to design the conceptual and navigational structure of Web applications and describe the view definition language. We introduce navigational contexts as the structuring mechanism for the navigational space. Some further work on designing Web applications with OOHDM is finally presented.