This mod allows you to walk up most inclines and removes almost all invisible walls in the game. Other than this, the mod has almost no impact on actual gameplay, save for a few glitches here and there. Below is an example of what you'll be able to do after installing it:

Pretty cool, right? Well, let's install this thing.

This shouldn't take long, maybe 10 minutes, give or take a few depending on how experienced you are with modding.

• Download the freeroam.zip file[fabletlcmod.com], then extract and run freeroam.exe
  
• Choose File frop the top menu and click Open
  
• Find your Steam\SteamApps\common\fable the lost chapters\data\Levels folder in the application's explorer and choose FinalAlbion.wad
  
• Make sure the boxes for TNG and Lev (Patched) are ticked, then click RIP!
  
• Choose the Steam\SteamApps\common\fable the lost chapters\data folder in the application's browser, then click Save
  
• You're now done using the applcation, close it
  
• Find the Steam\SteamApps\common\fable the lost chapters\data\Levels folder in your file browser of choice
  
• Rename FinalAlbion.wad to something else, I renamed mine to "FinalAlbion (no barriers).wad", if you want to play with barriers again just rename the file back to FinalAlbion.wad

Now you're all set! Get out there and take some screenshots!

Unfortunately there are still a few invisible walls, but this shouldn't be an issue as you need to get far-ish out to run into them.

Going through water is difficult in most spots, and it can take a while to get out. The only solution to this is don't go for a swim!

All credit for this mod goes to The Fable TLC Mod Wiki.[fabletlcmod.com]

Update 9/17/21: I'm seeing a few people in the comments claiming the linked file contains a virus. This isn't true, the file I linked above is the exact one that I used back in 2013 when I wrote this guide. It's probable that some virus scanners are having false positives, but both Windows Defender and Malwarebytes don't seem to have an issue with it.