reflecting pool
This tag describes a structure, usually framed in stone or concrete, designed to hold a shallow pool of still water for reflecting the surrounding area. They are usually found in parks or formal gardens and often features the reflection of a monument or an important building.
Famous examples include the one found at and reflecting the Taj Mahal, and the one at the National Mall in Washington D.C. that reflects the Washington Monument.
For a simply reflective surface of water in general, see reflective water.