Pastpin is a cultural search engine that aims to showcase the 7M historical images available from Flickr Commons.
Users are prompted to add new metadata (geocodes, temporal data) to existing images that they may recognise based on their current location. The goal of the project is to crowdsource spatial and temporal metadata for these objects.
Visitors to the site can search or browse by using free text, or by going directly to the map and clicking on a thumbnail to view images directly.