From the Federal perspective (the National Register of Historic Places is part of the National Park Service), a property owner can do whatever they want with their property as long as there are no Federal monies attached to the property.
I think you probably mean the metaphor of piercing eyes, it means someone who has a really intense look in their eyes. Sometimes it could be that the colour of their eyes is quite different, like a really icy blue colour. piercing eyes are eyes that can see straight through a person. SUPP is right.
Tiger's eye (also called Tigers eye or Tiger eye) is a chatoyant gemstone that is usually a metamorphic rock that is a golden to red-brown colour, with a silky luster. A member of the quartz group, it is a classic example of pseudomorphous replacement by silica of fibrous crocidolite (blue asbestos).