It might stink but for connoisseurs of Vietnamese food, a visit to this fish sauce factory is like a pilgrimage. Nuoc mam is the essential condiment of Vietnamese cooking, and they don't make it any better than on Phu Quoc. There are about 100 nuoc mam distilleries on the island, but Khai Hoan is the one most visited by tourists. It is right in the middle of Duong Dong, just a short walk from the markets, and admission is free. As Victoria Allman reported, the secret of Phu Quoc's nuoc mam success is a small silver anchovy called ca com. Copious quantities of this fish are dragged out of the Gulf of Thailand every night, and then left to ferment for a year here in 3000-gallon vats. As you would expect, all these fermenting anchovies create one hell of an odor. Allman wrote: "As I entered the factory, the smell hit me like a door being slammed in my face. It took my breath away." Needless to say, she said the little thimble of nuoc mam she was offered to taste-test tasted divine, but unfortunately airline policies prevented her from taking any of it home with her. That's the rule, at least, on Vietnam Airlines flights. Another fish sauce factory you can visit, this time in the An Thoi area, is Nam Huong.