On the O'Reilly page at http://www.checkio.org/station/oreilly/
Before you unlock the other 3 stations, there are images for each at the top of the challenge list. Directly below the text: "Collect points to unlock new stations"
The missing image's URL is:
http://www.checkio.org/static/imgv3/stations/codeship/locked.png
Just wanted to pass this along to checkio staff so that it can be corrected.
Edited to Add:
This image url is also coming up 404:
http://www.checkio.org/static/imgv3/stations/codeship/unlocked.png
Created at: Nov. 1, 2015, 8:41 a.m.; Updated at: Nov. 3, 2015, 8:23 a.m.