Cambodia to Laos

Flew from Bangkok to Siem Reap for Angkor (Cambodia), then to Pakse in Southern Laos, then Vientiane from where we went by bus to Vang Vieng (not shown but it's about half way between Vientiane and LP) and finally Luang Prabang, returning from there to Bangkok. Here's a map for anyone who doesn't have it in their head: