Jungle Book
The road from Phnom Penh to Siem Reep - home to the legendary temples of Angkor was horrid. OK, I only knew they were legendary after watching a trailer on Discovery Channel, but they might have added a parental advisory note about that road. For the first 100kms or so, no problems, but then the beastly thing deteriorates into a sandy, pot-holed, gravelly mess. I never knew that so many different types of awful road surface existed.