ArchNet: An international online community for architects, planners, urban designers, and scholars, with a focus on Muslim cultures & civilizations.
ARTSTOR: "The Public Collections are a freely accessible library of images and other media where you can search and browse collections with tools to view, share, download, cite, and print media. Institutions that subscribe to JSTOR Forum, a Web-based service for cataloging and managing digital collections, can share their content as Public Collections."
Catena: Digital Archive of Historic Gardens + Landscapes: The Digital Archive of Historic Gardens and Landscapes and its companion website, 'is envisioned as part of a larger, typologically organized archive of digital images with accompanying educational materials. Images and intellectual content can be used only for educational purposes'.
Cyburbia: An urban planning community sharing experiences about urban planning practice, planning adjacent topics. Registration required.
Europeana: Provides access to millions of books, paintings, films, museum objects and archival records that have been digitized throughout Europe.
Planetizen: is a 'fiercely independent platform that creates, curates, and amplifies stories and resources to inform planning and people passionate about planning'.
PlannersWeb: UK based web planning portal. Contains good resources for Urban design information.