It's located off the trail to the north between Hillcrest and the mountains north of Udgaard.

You get clues to this from the goblin outpost helpfile. "Established near Hillcrest", "Building their home within the forests by the mountains", "they raid nearby settlements for slaves and
supplies that they then trade with Udgaard". Lots of area help files are similar to this in that they have clues and some even have general directions to where they may be located.

As a good rule of thumb, if there's anything you have a question about, try the help file system. And keep in mind you don't even have to be perfect. You can even view help files off line by typing what you want in the search function at carrionfields.net

Something I learned just today due to this little topic, by typing help a, is:
"TAX TAXES (68)
Carrion Fields charges a tax on the wealthiest players to help pay for work on the player's hometown's roads. This tax amounts to 50% of all
copper above 250,000 coins, each and every time you log on. Keep your money in a bank to avoid this."

Not even in CF is a person exempt from taxes.. FML