Wikipedia

More detailed information can be found on https://wiki-insights.epfl.ch and an interactive demo at https://wiki-insights.epfl.ch/activity-graphs/

You can download a dump of the english wikipedia graph, which you can directly import into a neo4j instance

The dump is intended for neo4j version 3.x and can be imported using the following command (make sure you do not have an existing wikipedia.db database as the command below will overwrite its content) :
sudo -u neo4j neo4j-admin load --force --from=wikipedia_nrc.dump --database=wikipedia.db

If you try to import it into neo4j version 4.x, you need to set the property dbms.allow_upgrade=true in /etc/neo4j/neo4j.conf before importing.

When you start the neo4j server it will upgrade the database s.t. it is compatible with version 4.x

The code used to process wikipedia sql dumps, along with instructions, is located on github