They are places of ritual and worship. They are typically large rings of rock for people to go through during ceremonies.
Some rings have been cut in mountains to provide the possibility to christen spaceships.
Apart from seeking Oneness, there is no ritual or ceremony, as nobody sees the point. For practitioners, these rituals would only distract from the truth.
Seeking Oneness is done through a variety of different active and passive practices. The goal being to be constantly immersed in it, including during sleep.
