Gardens of mental delight
A few interesting approaches to conceptual gardening. The first one, if for nothing else, the dynamic title alone: The Garden of Cosmic Speculation. Located near Dumfries Scotland, it's a private garden (open one day a year) created by Charles Jencks and Maggie Keswick. Inspired by scientific concepts such as fractals and black holes, it is one of the most unique gardens in the world.
On a smaller scale, the Toronto Music Garden, a public park on the city's harbourfront, is an interesting garden created by world cellist Yo Yo Ma and landscape designer Julie Moir Messervy. Inspired by Bach's 'Six Cello Suites,' each movement is represented by its own smaller garden that serves as part of the continuous flow of the piece. In the summer audio tours are available that play music selections as you walk through the different movements. It's also not unusual to see the occasional inspired musician practicing somewhere in the park.
This garden is even more exclusive as it's not open to the public. Splice Garden is the outdoor lunch grounds for the faculty of Whitehead Institute for Biomedical Research in Cambridge, Massachusetts. It was created by David Baltimore who had to work around various constraints (extra weight, maintenance, etc.) that didn't allow for live flora. All greenery in the garden is artificial, and uniquely placed. The two halves, inspired by French and Japanese styles, represent the controversial dangers of gene splicing.