The princess bath was made of beautifully carved stone. You can see the three level symbolism carved into the rock. Throughout the inca ruins in Peru and the Tiahuanaco ruins in Bolivia, you will see the three levels of their belief system. The three levels were heaven, the present/living and the underworld. These were represented by the condor (heaven), the puma (present/living) and the snake (underworld).
If you look at the small pool at the top of the bath, our guide pointed out that the water flows from its source at an angle. The incas would put sand in that top small pool. As the water comes from its source, it will swirl around in the top pool to "filter" the water before it touches the princess. He put a leaf in the top pool and showed us that the leaf just circled around in the top pool.
The next thing he showed us was amazing. The engineering put into the design of this bath was amazing. The guide told us that the queen kneels in the pool with the water coming down on her head, she would simply run her fingers across the top of the fountain (where the guide is touching) and the water would stop flowing. She or someone would then flick water back at the fountain and the water will resume. I got video of this, its amazing.