In 1996, the World Heritage Committee added the Historic Center of Oporto, Portugal, to the World Heritage List, recognizing its outstanding value, identified by its urban fabric and its many historic buildings. The area’s value is the result of a complex topography, articulated through streets, lanes, alleyways, stairs, and squares, while its architecture (residences and monuments) projects cultural values accumulated over successive eras. In the state of art section, this chapter presents some significant references and visual resources that contribute to the understand city´s urban development and to visualize the city in the past. This chapter presents two case studies of the authors’ attempts at visualization of that historic district. One describes a 3D scale model—Oporto’s Medieval Scale Model - and the other is a virtual reality project—Virtual Porto in the Sixteen Century—both shown as examples of thorough research, careful documentation of processes, and clear and approachable presentation. The authors also consider the potential of expanded development of such presentations, in light of uses in tourism and furthering greater knowledge, with the goals of facilitating the process of heritage conservation and the dissemination of information. As such, the two case studies are viewed in terms of principles of the London Charter regarding the creation of virtual heritage, as well as cite other examples of projects in European cities.