She is mysterious because she never completely reveals herself to anyone. She is the focus of divine motherhood found in the Ancient Egyptian mystery schools. The Temple of Isis is one of the first a Light Traveler will find in the search for inner truth. A powerful and focused desire to bring love into this world opens the portal. You must connect your heart to the challenge of bringing motherly love into the physical world.
Feminine power is focused on the energy of giving from the self to create divine life.
That's the key. The outer temples or marble are now gone, but they aren't necessary. The inner Temple of Light remains. When the initiate Aristides entered the temple of Isis he saw a Light and other unutterable things conducing to salvation. Find the temple and you likely will too.