Boreth:

Is the spiritual centre of the Klingon Empire.  It is a place of pilgrimage for many Klingons, The Class-M planet is the most sacred place in the Klingon Empire.  According to legend it is the place where Kahless the Unforgettable will return from Sto-Vo-Kor and reunite the Klingon people.

Klingon Clerics:

The monastery is home to a group of clerics. In 2369, the head cleric is called Koroth; like the other senior clerics, he wears a robe that is part ceremonial garment and part battle armour.

The clerics have been on Boreth for centuries, waiting for Kahless to return. They have very little influence on the way the Klingon Empire is governed, and the leader of the Klingon High Council does not need their support.

The clerics are responsible for teaching others about the sacred texts, which record the wisdom of Kahless, and for guiding the many visitors to their planet.

The Pilgrims visiting Boreth try to enter a visionary state, in which their greatest hope is to see a vision of Kahless himself.  In order to do this the pilgrims fast and attend a number of ceremonies.  Typically, male and female pilgrims sit in small groups of no more than eight, with their eyes closed, around a ceremonial stone fire pit.  The pilgrims dress in traditional Klingon robes and recite mantras, pray, and meditate.

Ancient promise:

The reason that Boreth is so significant to the Klingons is recorded in Story of Promise.

According to this legend, after Kahless the Unforgettable had united the klingon people and given them the laws of honour, he saw that his work was done.  He gathered his belongings and went to the edge of the city to say goodbye.  The people wept, because they did not want him to go.  Kahless told them "You are Klingons, you need no one but yourselves.  I will go now to Sto-Vo-Kor.  But I promise one day I will return."  Then Kahless pointed to a star in the sky and said: "Look for me there, on that point of light." 

That promise was made over 15 centuries ago.  Since then, the followers of Kahless have established the monastery on Boreth - one of the planets that circles the star to which Kahless pointed.

Kahless's monastery:

The monastery complex itself is composed of at least 5five separate buildings, like pagodas, in the elaborate traditional Klingon style of architecture.

Life in the monastery is extremely simple.   Even though the Klingons had advanced technology by the time they reached Boreth, the buildings are built out of blocks of stone and the heavy doors are made of wood. 

False hope:

In the 2360's the clerics on Boreth become convinced that they must act to save the Klingon Empire from moral decay.  In order to do this, they use an organic sample from the real Kahless to create a clone in a secret laboratory on Boreth.  They try to convince the Klingons that Kahless has really returned, and even though the truth is revealed, the clone eventually becomes the ceremonial Klingon Emperor.  Despite the clone's existence, many Klingons still visit Boreth in the hope that the real Kahless will one day return.

FACTS:

Although the monks on Boreth have some artefacts that were owned by Kahless, others were lost a thousand years ago in the Hur'q invasion.  Others are kept on the Klingon Home world.

Boreth is not the only place Klingons seek visions; the same rituals can be used anywhere.

Klingons who are trying to enter a visionary state use a circular fire pit that burns with an intense flame.  The fires produce a lot of heat and smoke.  Pilgrims stoke the flames until the temperature is almost unbearable.