When viewing the town map of San Francisco, if you press 5, you travel to an unused area- it is a small black rectangle. The hexes there are plainly visible, and have 'unused art' written on them. Moving the cursor moves it but still shows the previous location, and this happens as well with moving the player.
If you want to go to the Vertibird crashing place from Klamath your game crashes. Simply go into the options and change the brutality to the lowest.
When viewing the town map of The Den, if you press 3, you travel to an unused area, this is the residential district with houses and residents inside, there is also junkies roaming in the streets. If you go north you will go to Den East Side but you won't be able to return in the previous location by the same way.
Crashing and freezing
Occasionally, upon attempting to skip the Interplay intro, you will freeze.
Recruiting Dogmeat at the Café of Broken Dreams by feeding him some iguana bits instead of just showing him the vault jumpsuit (he recognizes it and joins you), the game may crash. If it does not, it lags excessively, and just exiting to desktop and restarting the game will stop it from happening again and you can pick up right where you left off at the cafe.
Sometimes specific save spots seem to get corrupted and, after loading, will display an error message and crash the game.