Longevity is held in high esteem and is one of the most frequent and popular subjects in Korean art. Enduring eternally and sustaining life, the sun, clouds, water, and mountains are the background for other symbols of long life in a landscape paradise. The pine and bamboo, noted for their hardiness and resiliency, are often compared to venerable old men. Various legends associate cranes, tortoises, and deer with happiness, good luck, and long life. Deer are said to be the only creatures able to find the sacred fungus, a supernatural mushroom of immortality.