External representations powerfully support and augment complex human behavior. When navigating, people often consult external representations to help them find the way to go, but do maps or verbal instructions improve spatial knowledge or support effective wayfinding? Here, we examine spatial knowledge with and without external representations in two experiments where participants learn a complex virtual environment. In the first experiment, which was pre-registered, participants had access to an accurate map or set of verbal instructions that they could study after learning the layout of target landmarks. We found no evidence of improved spatial knowledge in a pointing task requiring participants to infer the direction between two targets, either on the same route or on different routes, although the map group could recreate a map of the target landmarks more accurately. However, overall improvement was high and was specific to navigation ability levels, even for the control condition. In the second experiment, we asked participants to generate their own maps or verbal instructions. Again, we found no improvement in spatial knowledge. However, as a methodological note, pointing was correlated with the accuracy of the maps that participants drew. Our findings add to a mixed literature on the role of external representations for navigation and suggest that more substantial intervention – more scaffolding, explicit training, or enhanced visualization – may be necessary to improve navigation ability.