"Waking, sleeping and dreaming are liminal activities, and the very act of breathing may be construed as liminal. Spirals, labyrinths, mazes, tors, mounds, stone circles, groves and sacred enclosures are liminal spaces opening into other realities and other modes of being and thinking — as are winding woodland trails, oak stands, clear streams and mountains (I find myself thinking of the Queen Mother of the West and the mythical Peach Blossom Spring here)."
"We each approach the liminal in our own way and our own time, and the lens through which we filter our liminal experiences is a unique and very personal thing. For some of us, the gateway lies through church services and collective ceremonies — for others it is private prayer, meditation and silence — for still others, the way is through loving observation of the natural world, personal ritual, carefully crafted rites of passage and the old seasonal festivals. Sunrise, noon, twilight and midnight are liminal times of day when according to ancient lore, divination and magic could be worked by those skilled in such arts — such times would have been fearful and vulnerable intervals for those without magical gifts or the protections of the Craft."
By Kerrdelune, Beyond the Fields We Know
Please, do take the time to read her excellent series of articles on the topic.