“The Magician’s Companion: A Practical & Encyclopedic Guide to Magical & Religious
Bill Whitcomb, 1997
XIV. Law of Interfaces
Power exists in the interfaces of things. These are the between places that are not entirely on thing or another. (See IX. Law of Association.) Traditionally, these places include caves, grottoes, towers, mountains, beaches, wells, crossroads, and cliffs. All the chief times of change of the day are considered to be powerful. These are dawn, noon, twilight (sunset), and midnight. Likewise, the solstices and equinoxes, the pivots of the year, have always been thought very important. There is a medieval legend that if a woman wished to become a witch she need only remove her cloths and stand between the high- and low-tide marks at the seashore.
There isn't much to say on this one. It is another pretty self-explanatory Law. But I would like to mention here that throughout our recorded history these between places and times have always been in the minds of humans. I believe that we have always known that there is something powerful and magical about these.