If you live in Japan or have been there during the period leading up to the New Year, you've probably noticed that some people display beautiful ornaments in front of their houses or on their front doors. These are called "kado matsu" and are often partly made of pine.
The shapes and forms of the ornaments may vary, but they are generally very artfully crafted.
Daruma dolls are also an important New Year's ornament. They are said to bring good luck.
...and when the New Year's celebrations are over in mid-January, some people communally burn them in huge bonfires. The event is called Dondo Yaki. There is a belief that throwing the ornaments away will bring bad luck, so burning them is the proper way to dispose of them. Another belief is that eating mochi cakes grilled on the Dondo Yaki fire will bring good health for the year.
If you are in the Tokyo area, a popular Dondo Yaki event is held every year in Machida's Oyama Dairi Park. The fire is lit at 1 PM and you can place your own ornaments to be burnt if you arrive early. The park is near Tamasakai Station (Keio-Sagamihara Line). They sell mochi rice balls on the spot. It takes about an hour to get there from central Tokyo.