(CNN) — The former imperial capital of Hue sits just below what was once the demilitarized zone between North Vietnam and South Vietnam and was, near the end of the war, the site of some of its fiercest fighting. You've seen it in newsreel footage -- and recreated (in England) in Stanley Kubrick's "Full Metal Jacket."
Hue is, in many ways, a city of ghosts, of memories and spirits -- and we play on that in Sunday's episode.
It begins with a camera movement inside a "spirit house" -- the dollhouse-sized shrines that many believers keep outside their homes and businesses. The Vietnamese are largely ancestor worshippers. Helping your deceased relatives into the next life -- and making sure they are happy while there -- is important.
On special days and holidays, families visit temples and pagodas and leave offerings, often food, sometimes replicas of money or appliances or luxuries for the departed. Things they liked in life that might make the afterlife more comfortable.
"One of the great joys of life is riding a scooter through Vietnam," says Anthony Bourdain.
Spirit houses, as I understand them, are designed to deal with the problem of hungry, dissatisfied spirits who may not be settled, who have, for one reason or another, unfinished business left behind. They sit out front, or near the house or store, usually filled with incense and offerings, in the hope of distracting the spirits away from the main destination.
In the weeks following the initial North Vietnamese taking of the city of Hue, many hundreds -- if not thousands -- of citizens, deemed dangerous or counterrevolutionary or otherwise undesirable, were summarily executed and buried in unmarked mass graves by the communist forces.
When U.S. Marines and the army of South Vietnam retook the city, it was only at the end of brutal, house-to-house fighting and finally, airstrikes, that Hue was retaken -- flattening much of the city in the process. Many, many people were lost, their bodies never identified or recovered. This, the inability to find the physical remains of a relative, is a particular agony to Vietnamese.
Haunted by ghosts
For this reason, this episode is haunted by ghosts. We hadn't intended it to be so. But that definitely emerged as a theme.
You feel it as you drive the streets and early morning rice paddies on a scooter, walk the parapets of the ancient citadel, look at the flag hanging in the mist across the Perfume River. At one point, a young woman I'm having dinner with casually mentions that her mother doesn't like her to go out after dark. Too many ghosts.
I don't want you to think that this episode of "Parts Unknown" is some kind of a bummer -- a depressing discussion of a war about which there are still strong feelings and disagreements here. It's not.
One of the crazily awesome, incongruous things about Vietnam that I've found from the first time I visited is how friendly, welcoming, quick to move beyond the past the Vietnamese are.
It is an incredibly beautiful country. One filled with passionate, proud cooks, and opinionated, enthusiastic eaters. You will see me with some old friends -- and you will, as always in Vietnam, see me eating some amazing food.
And if you thought pho was the best thing ever? Wait 'til you see bun bo hue.
Anthony Bourdain travels back to Vietnam, the place that changed his life. Tune in to "Parts Unknown," Sunday at 9pm EST.