Archive sites may work on the basis of a web crawler to look for specific kinds of obsolete content, or they may work on the basis of user submissions. Some work on a combination of the two. Other archive websites might pull from a specific venue. For instance, the massive GeoCities web domain that was taken down years ago was a repository for many thousands of user-created sites. A GeoCities-specific archive site might take various pages from this obsolete domain, and move them to a place where web users can continue to access them.