We've seen quite a few 'museums' in Vietnam where they've done everything wrong and the result is thoroughly forgettable.
Son My is the polar opposite -- they've done everything right and the result is informative, very unsettling, and is liable to be one of the key experiences you'll remember from your trip.
Most people have heard of the massacre, which is called My Lai by the Americans -- something of a misnomer, but you'll learn all about that at the museum. Basically, some American soldiers lost their minds and rather than trying to systematically rout out possible Viet Cong sympathisers, they decided to execute every man, woman, child and infant in two small hamlets within the village of My Son. Several other American soldiers, who had not lost their minds, threatened to open fire on their own troops if they didn't stop. This slowed the massacre down, and the good guys were able to whisk ten potential victims to safety in a helicopter. The museum vividly recounts the incident in disturbing detail, castigating the culprits and lauding the heroes of the day. American veterans visiting the museum routinely break down in tears, and it was very easy to see why.
The museum itself is filled with maps, dioramas, artefacts, and plenty of informative legends in English. To that have been added a gut-wrenching series of photographs taken before and after the day -- some of the latter are grisly colour photos of the dead. There's also a life-sized recreation of four soldiers executing villagers.
Just to the west of the museum lies the village itself, which has been preserved, largely as it was after it was burned to the ground, though one home has been reconstructed to give an idea of what the place was like before. They've added some slightly comical cement replicas of dead cats, dogs and cattle, but the site still powerfully evokes the aftermath of the attack. The small plots of vegetables surrounding the homes are still tended by survivors of the attack to this day.
Of course, countless innocent Vietnamese citizens were also tortured, imprisoned and executed by the North Vietnamese government and its army, before, during and after the war. The Son My museum is, in that respect, a very one-sided account of history, but it's still an incredibly effective testament to the brutality of war.
Admission is 10,000 dong. English-speaking guides are available and highly recommended -- there is no charge for the service, but a generous donation is appropriate.
How to get there
When Westerners show up in Quang Ngai, all the xe om drivers assume (rightly) they're there to visit Son My, so you'll get no end of offers. A roundtrip ride from town on a motorbike is about 15 km each way and should cost 100,000 dong, 70,000 if you bargain hard. A taxi should cost about 500,000 dong total for up to four people. You can also stop in at Quang Ngai Travel at the Hung Vuong Hotel -- they'll make arrangements for you free of charge. The driver is unlikely to speak English, but the museum provides its own English- and French-speaking guides.
To get to the museum on your own, take Quang Trung out of town north across the bridge and take your first right on Highway 24B -- the My Tra Hotel sits on the corner of the intersection. The museum is about 10 km further down on the left. The beach is less than 2 km past it at the end of the road.
Even if you're not on an organized tour departing from some other city, you can still visit Son My in transit. Coming from the south along Highway 1A, pass Quang Ngai town via the overpass, and just where it touches down on the northern bank of the river, there's a sign for Highway 24B and a sharp right-turn exit. Heading from the north, you'll want to get off Highway 1A just before the overpass, which is marked by a sign indicating that you're entering Quang Ngai. Local buses will drop you off here rather than in town if you ask nicely. There are usually some xe om drivers hanging out who will take you to the museum -- it should only be about 40,000 dong round trip from here, but good luck with that. You can return here when you're done and catch one of the 16-passanger vans heading north or south along Highway 1A.