He wrote Journey Without Maps about his trip, on which he nearly died.
He brought along his 23-year-old cousin. She wrote Too Late to Turn Back about the trip. She viewed things a little differently, of course.
One of the surprises she found was that it was not an "adventure"--except perhaps in the sense of being a nasty uncomfortable thing that made you late for dinner. It was tedious, and the heat and monotony drained body and mind. At the end of it all, she said it was worth it.
I spent almost all my time in the developed area on the coast, and what wasn't there was spent close to main roads and extractive industries. I never saw what she did in the interior. And the Monrovia I saw was a much bigger and richer (relatively) city than the one she saw.
Read it. And Graham's too. They each see Dr. Harley differently.
UPDATE: The waterfall they each describe can be partially seen illustrating this BBC story.