In-Bed Fountain. Bring a fountain to life by tucking it into a planting bed. In this eye-catching example, a pump sends water cascading out of the sculpture and into the pond. A colony of parrot's feather grows in the pool.
Argentinian artist Leandro Erlich created this illusion of people walking underwater called The Swimming Pool, for The Century Museum of Contemporary Art in Kanazawa, Japan. It's a piece of glass with water on top of it, and empty space on the bottom.