Research on cognitive modeling of information search and Web navigation emphasizes the importance of “information scent” (the relevance of semantic cues such as link labels and headings to a reader's goal; Pirolli & Card, 1999). This article shows that not only semantic but also structural knowledge is involved in navigating the Web (Juvina, 2006). This article argues for considering both semantic and structural knowledge in modelling Web navigation. A cognitive model is proposed that uses information scent to account for user's judgments of relevance (a semantic dimension) and “path adequacy” (the semantic similarity between a navigation path and a user's goal) to account for user's efficiency in traversing a Web structure (a structural dimension). Two empirical studies show that abilities to represent and manipulate spatial structures are complementary to semantic abilities in accounting for Web navigation performance.