Sinkhole may exhibit a visible opening into a cave below. In the case of exceptionally large sinkholes, such as the Minyé sinkhole in Papua New Guinea or Cedar Sink at Mammoth Cave National Park in Kentucky, an underground stream or river may be visible across its bottom flowing from one side to the other. Sinkholes are common where the rock below the land surface is limestone or other carbonate rock, salt beds, or in other soluble rocks, such as gypsum, that can be dissolved naturally by circulating ground water. Sinkholes also occur in sandstone and quartzite terrains. As the rock dissolves,
Into the Void (Black Sabbath song) Into the Void (Black Sabbath song) "Into the Void" is a song by Black Sabbath, released in 1971 on their album, "Master of Reality". An early version of "Into the Void" called "Spanish Sid" was released on the deluxe edition of "Master of Reality". It is written in the key of C# minor. Various artists have covered the song, including Soundgarden, Kyuss, Monster Magnet, Melvins, Sleep, Dr. Know, Cavity, Exhorder, Lumsk, Dimmi Argus and Orange Goblin. In Soundgarden's version, the original lyrics are replaced by words of protest by Chief Seattle, which fit the metre of the song. At the