Construction in Los Angeles may have exploded during the postwar era, but as a new interactive map shows, the wide age range of its buildings might surprise you.

Using open data from local governments, built: LA visualizes the age of roughly 3 million buildings across L.A. County constructed between 1890 and 2008. Drag your mouse to explore the vast web of communities and neighborhoods, hover over individual properties to discover birth years, and double click to zoom in further.   — citylab.com

Open data, and the interactive mapping and data visualization that can come of it, has become a de facto engagement and storytelling tool among contemporary journalists, social justice activists, and civic-minded technologists. But despite its allure, open data’s potential for fostering civic engagement and creating transparency and dialogue is plagued by issues of usability, access, and quality control. — urbanomnibus.net

For more than a century, [Helsinki] has funded its own statistics bureaus to keep data on the population, businesses, building permits, and most other things you can think of. [...]

Helsinki and three of its neighboring cities are now banding together... Through an entity called Helsinki Region Infoshare, they are bringing together their data so that a fuller picture of the metro area can come into view. — citiscope.org