What’s inside this crater in Madagascar? Satellite photos show a village growing from nothing, starting in 2008. Nearby towns seem to know nothing about it, not even its name.

The Vox investigation is a case study in Open-Source Intelligence (OSINT), making for a gripping detective story, plus a marvellous lesson in sociology, geography and geology.

…And what’s the killer technology used in the investigation? Post-it notes!