Kevin Lynch's 1960 study The Image of the City gave wayfinding its modern vocabulary: paths, edges, districts, nodes, landmarks. He was describing how people build mental maps of cities. He could just as easily have been describing how people build mental maps of websites, which is presumably why every UX team eventually rediscovers his terms without meaning to.
Landmarks over labels
A confused person in a hospital doesn't remember they turned left at "Radiology — Corridor C." They remember the mural, the different floor colour, the vending machine. Landmarks work because they're recognised instantly and hold up under stress, while text labels require reading, which disoriented people are bad at. A distinct visual anchor on a busy page — a consistent logo position, a recurring colour block — does the same job as a mural at a corridor junction.
The rule of three decisions
Wayfinding designers generally assume a visitor can hold about three consecutive navigation decisions in mind before needing reassurance that they're still on track. Past that, they need a "you are here" marker — in a building, a map; on a site, a breadcrumb trail or a persistent section header. Sites that bury content five clicks deep with no reassurance along the way are asking visitors to do what most hospital signage systems were explicitly redesigned to stop asking of patients.
Good wayfinding is invisible until it's missing, at which point it's the only thing anyone notices.
The next time a navigation menu feels obvious, it's worth asking which building it's quietly been modelled on.