Laufarija - Cerkno's own rite of spring
Its central event is a mock trial in which the Pust - a horned creature clad in moss that personifies winter - is convicted to death for all the bad things that have happened locally and the world at large in the past year.
Apart from a jury and a judge, the whole affair involves a cast of 25 different costumed characters, known as the Laufarji or Runners, named so after the figure who is always running around.
Each member of the family wears one of the distinctive costumes and masks carved from lime tree wood. Some of these are archaic, originating from pagan times, while others are new additions.
These represent either a local trade or craft - such as the innkeeper - or display certain character traits or afflictions - like the Scabby Man or the Drunk and his wife.
The festivities begin the first Sunday after the New Year's, when the first Laufar makes his appearance in the streets. Every Sunday more figures appear, so that the group is complete on the Sunday before Ash Wednesday.
In the run-up to the festival, the Laufarji make their rounds in Cerkno and nearby villages with good wishes for health and an abundant harvest, the typical invocation being that "the turnip may be bigger".
In preparations for the main event, the costumes for three of the characters are made anew every year from moss for the Pust or the Shrovetide Man, spruce branches for the Spruce Man and ivy for the Ivy Man.
In case of the latter, it takes hours of painstaking work to sew some 10,000 ivy leaves on to the costume - a job taking five to six hours a day for three weeks during which accidents are bound to happen.
On the Sunday before Fat Tuesday, the Pust is hauled before a court set up in the town square and charged with a long litany of crimes, ranging from nasty weather to potholed roads and useless politicians.
He makes several futile attempts at fleeing the scene, only to be dragged back by the Thread Men, the running figures who in the meantime are doing their best to scare away the children.
Off-stage, the Drunk and his roller-pin-wielding wife get up to all sorts of crazy antics to the amusement of the crowd, while most of the other members of the family follow the proceedings calmly.
Being conducted in the local dialect, the ceremony can be a bit mystifying to an outsider, but it gives the locals much to talk about, which is what keeps the tradition alive.
The reading of the charge sheet is repeated on Fat Tuesday. Found guilty by the jury, the Pust is convicted to death by mallet, a wooden hammer dug up for the purpose hours before.
After the execution, carried out by the Old Man, the Pust is taken to the nearby inn, where he is laid in state and kept so until midnight when by tradition the carnival time ends.
In absence of written records, it is not clear how old the Laufarji are or where they come from, but experts believe they originate in pagan times.
For decades or even centuries, the ceremony was performed according to unwritten rules handed down by word of mouth, for the last time in 1914, when the World War I broke out, after which the festivities were banned by the new Italian authorities.
After a space of four decades and two world wars, the carnival was revived in 1956 with the help of the elderly locals who were still able to remember the old tradition.
Upon its revival, the Laufarija family comprised 14 figures, but their number grew by the years. All of them are on permanent display at the Cerkno Museum, while the original masks are kept by the Ethnographic Museum in Ljubljana.