There are not many roads to go to Mondulkiri, a must-see region of Cambodia. To get there, I strongly advise you to take the national road. Fairly simple and well-maintained road (according to Cambodian criteria), it makes it possible to reach the town of Snuol, the last stage before attacking a bit of relief. The Vietnam border is very close. Be careful: this road is frequented by a lot of trucks. Feel free to pull to the right as they won't push each other (the bigger vehicle has priority).