Norc is the first web service allowing its visitors to do virtual walks through cities in Central and Eastern Europe, while using a navigation system switching through panoramic images taken in the street, a system also called street-view or street-level imaging. The images provided to the visitors are taken based on a proprietary technology of generating views that are geo-referenced in the street. The technology consists in using cars equipped with a proprietary panoramic photographing device based on 10 cameras, correlated with a Differential Global Positioning System (DGPS).