Sof Omar 3one of the world’s biggest, Africa’s largest cave, and marvelous underground world is located 120 kms from Goba town. It is formed by Web River, which rises from Bale Mountain. The beauty of the cave comes from the untouched and savage aspects of the huge main passages, shape of the sections of the galleries, the white color of the lime stones, the great number of entrances, and bewitching noise of the river. The 42 internal entrances and its total passages distance of 16 km, its 1.7 kms tourist line, which crosses the river seven times and takes about an hour walking. Sof Umar cave is a reputed historical Islamic heritage attributed to Sheikh Safiyyullah Umar (Sof Umar). The Sheikh is said to be the nephew as well as the disciple of Sheikh Husein. He lived, worshiped Allah in the cave, and taught Islam to his followers many centuries ago. Sof Umar is also noted for forest birds, which attracts many Ornithologists. The endemic bird, Salvador serin is localized here.