The COVID-19 pandemic outbreak (in early 2020) has dictated significant changes in society and territories by anticipating trends, changing priorities, and creating challenges, which are manifested in the territories. These are influenced by the levels of economic, cultural, and social restructuring, in the measures implemented by public administration or in attempts to redefine strategies for tourism destinations. This paper examines the perceptions and behaviors of tourists before and during COVID-19 in the municipality of Porto, the main area of the Porto Metropolitan Area, in Portugal. Research was based on the application of a questionnaire survey, probing the sensitivity of tourists to the crisis in the decision-making of daily routines, as well as future travel plans in the presence of a serious health concern. A total of 417 surveys were collected in the summers of 2019 and 2020. In addition to descriptive statistics, this paper also includes the results of the analysis of explanatory factors, being a reference for future studies. There were significant changes in the use of public space and the way tourist visits are handled, namely: (i) the concentration of visiting time (shorter visit than usual in certain tourist profiles); (ii) spatially limited visiting areas; and (iii) the ability to attract standard tourists from certain countries where tighter lockdown rules were imposed. Main implications of this study are reflected in the challenges that are imposed on the local agenda, where traditional problems are added to the responsibilities in crisis management and the ability to establish a third order of intervention in tourism.