In Chinese metaphysics,  when an Feng Shui master looks at a direction and form of a house or property, describes the directions thru mythical animals such as white tiger, red phoenix, azur dragon, and black turtle.  Black turtle is a symbol of protection that sits at the back of the house or property.  A turtle lives a long life and represents its’ strength and ability to have these qualities.  Observance of nature and beings living in harmony is a universal principle that is timeless.