I particularly enjoy german Osterfeuer (Easter Fire) although it's usually not the old christmas trees you burn (they get in the trash around january) but all the clippings from your garden. Years ago you could create your own Osterfeuer in your garden but now you can partake in few official but big ones. It's also a great way to get rid of all the twigs and stuff from your garden, you just have to deliver it to the place. (And each year you hear people complain that the fire of the last year was bigger... WAAAAAY bigger!)