The Mines Advisory Group's visitor centre on the main street of Phonsavan is small, free, and easily the most important museum in the region. A series of panels and short documentaries explains the secret war that the US Air Force prosecuted against Laos between 1964 and 1973 — the heaviest bombing campaign in human history per square kilometre — and the slow work of clearing the unexploded ordnance that still kills and maims Lao people every year.
Survivors and de-miners speak in the videos. Defused cluster bomblets, white phosphorus shells, and the heavy metal detectors used by clearance teams are on display. Visit before going to the jar sites and the broader context of those white-and-red marker stones makes sense.