"Defeat the flying menaces and bomb their nest to teach them a lesson. And that lesson is genocide."

If you followed the guide, you should get the "Pest Control" achievement.

"When you hit another fork turn down a road to the south"

not the road that goes south right after the first fork, but further.

"Continue east from the house and jump across several more gaps"

Not east, but west, and after climbing some legdes, then road turn east. It's more like zig-zaging.

I do realize this is an old post, but I want to make a correction for others that come along in the future. The entrance west of Urialla Harbor is not a death trap if you are careful and worth attempting.

Go to near the west end of the hole on the southern side and jump to a ledge and proceed down.

Spoiler: You will face a couple of Gargoyles.