Recently, a player was able to purchase an Xbox 360 devkit that belonged to the creators of Grand Theft Auto IV. An early build of the game with cut content was preserved on it.
Tech enthusiasts studied the files and were able to run this build of GTA IV:
Modders published gameplay of GTA IV online — Niko climbed onto the restored ferry:
They also showed the beta version of the map and compared it to the final version. Players noted that they had already found such a map in the release version of the game in car dealerships, but now it is possible to study it in high resolution: