The shivalingam is probably the most important Shaivite symbol. The symbol may take many forms, most usually a post with a rounded top. This form makes the pouring of sacred fluids such as milk or water easy. Though many shivalingams are man-made, some are natural. Naturally occurring oval stones from the Narmada River are often used in worship. Some temples also have natural shivalinga, among the most famous being the Amarnath temple, which has a natural ice lingam.
There are many symbolic meanings to the shivalingam. The oval shape represents the universe. The shivalinga is sometimes depicted with four faces. This form is known as the Panchamukha, or five faced shivalingam; the fifth face is said to be invisible and looks directly upward to the heavens. The panchmukha Shiva is a form of sadashiva or eternal Shiva.