Thin places between the worlds?

Your information is quite accurate. I think that the concept arises from Celtic lore with those times when the veils thin occurring at Beltane and Samhain, the major autumnal and vernal Celtic festivals. It's said, too, that at those occasions the Fey Folk (faeries) often interact with humans, luring the unsuspecting into their "lairs" where time for humans seems to slow so that when they emerge from Faerie Land, many Earth years have ped, and their friends and relatives are long dead. There is another concept of Ley lines which are said to connect power vortexes, a grid which covers the Earth, and those vortex points are places where the veils may also be d. The "veils" shroud gateways between the Worlds of Matter and Spirit or between Planes of Consciousness. Of course, all of the preceding is "lore"; I've studied most of the disciplines which collectively are known as the Western Mysteries or the Western Tradition of Magick. However, the agnostic in me does not allow me to believe; still, I am forever fascinated!