An astral guardian is an entity, ghost, or thought-form that guards a place, especially of a sacred nature. An astral guardian is usually invisible but may be perceived psychically.
An astral guardian can be summoned by ritual when a sacred place is consecrated. Astral guardians may be spontaneously attracted to a place on their own accord. For example, the ghost of someone who had a strong personal connection to a place while alive may linger to guard and “haunt” the place after death. Thought-form guardians can be created by magic ritual.
Angels and fairies also act as guardians of places.