Once a year, in the eighth month of the lunar calendar (usually September), there's a full moon that looks especially big and bright. Vietnamese, Chinese, Korean and Japanese families all celebrate it.
In Vietnam it's Tết Trung Thu — "the festival of the middle of autumn". After Tết, it's the second-biggest celebration of the year. And it's mostly for kids.
On the night of the festival, children go out into the streets carrying paper lanterns — lồng đèn. Some are stars. Some are fish, butterflies, dragons, rabbits. Inside each lantern is a candle (or a tiny light bulb these days).
The streets fill up with bobbing coloured lights and the sound of singing. The children sing the festival song:
Tùng dinh dinh, tùng dinh dinh,
Đêm rằm tháng tám…
("Boom-ding-ding, boom-ding-ding, on the full-moon night of the eighth month…")
The most special food is the mooncake — bánh trung thu. A small, dense, round cake with intricate patterns pressed into the top. Inside: lotus seed paste, salted egg yolk (representing the moon!), nuts, and sometimes a whole chestnut.
Mooncakes are rich. Most people slice one into eight tiny pieces, share with family over tea, and try not to fall asleep right after.
Adults gift each other beautiful boxes of mooncakes for the weeks before Trung Thu — like Christmas cards, but edible.
You'll also hear the lion dance — múa lân. Two dancers (one is the head, one is the back legs) wear a giant colourful lion costume and dance to a loud drum. They visit shops and homes, "blessing" them for good luck. Shopkeepers feed the lion red envelopes of money.
The drums are loud. Tiny kids cry. Older kids cheer. Everybody eats mooncakes.
Vietnamese grown-ups say that on Trung Thu, if you look closely at the moon you can see a man sitting under a banyan tree — chú Cuội, who one day grabbed the roots of his magical tree as it floated up to the moon, and has been stuck there ever since. Next time you see a full moon, see if you can find him.
Most Vietnamese festivals are about ancestors — paying respect, remembering people who have passed away. Trung Thu is the opposite: a whole festival just for children. The grown-ups buy the lanterns, make the mooncakes, hire the lion dancers — all so the kids can have a magic night under the brightest moon of the year.
One day, you'll be the grown-up. You'll buy the lanterns.