A krathong is shaped like a small lotus flower. It is built from a slice of banana tree trunk for the base, banana leaves folded into petals, marigolds and orchids pinned around the edge, and three things in the middle: a candle, an incense stick, and a tiny coin. Many families fold them together as a craft activity in the afternoon.
When it gets dark, people walk down to the nearest river, lake or fountain. They light the candle, make a quiet wish for the year ahead, and gently push their krathong out onto the water. Hundreds of little flickering lights drift away together. From a bridge, it looks like the river has filled with stars.
Loi Krathong is also a thank-you to the rivers, because the rivers give Thai families water for their fields and for cooking. People sometimes say it is a way of 'asking the water for forgiveness' if they have used too much or kept it muddy. The festival is gentle, quiet and very pretty.
In the north of Thailand, around Chiang Mai, people also let go of paper lanterns called khom loi at the same time. These are like hot-air balloons made of thin paper. As they rise into the sky, the rivers below twinkle with floating krathongs and the sky above twinkles with floating lanterns. The whole town lights up.