The karesansui (or karesenzui, kosansui, kosensui 枯山水: "dry landscape") style originate from zen temples. These have no water and few plants, but typically evoke a feeling of water using pebbles and meticulously raked gravel or sand. Rocks chosen for their intriguing shapes and patterns, mosses, and low shrubs typify the karesansui style. The gardens at Ryōan-ji, a temple in Kyoto, and Daisen-in, created in 1513, are particularly renowned.
Other gardens also use similar rocks for decoration. Some of these come from distant parts of Japan. In addition, bamboos and related plants, evergreens including Japanese black pine, and such deciduous trees as maples grow above a carpet of ferns and mosses.
Shakkei (借景), "borrowed scenery," is a technique used to integrate the garden with mountains, buildings, or other objects outside its boundaries. A middleground element, often carefully maintained plantings, blocks unwanted elements and frames the desired view. This middleground integrates the "borrowed" view into the garden's design. The viewer is encouraged to see all three areas - foreground, middleground, and background - as a single garden.
http://en.wikipedia.org/wiki/Japanese_garden