A Jyotirlinga or Jyotirling or Jyotirlingam is a shrine where Lord Shiva, an aspect of God in Hinduism is worshipped in the form of a Jyotirlingam or “Lingam of light.” There are twelve traditional Jyotirlinga shrines in India.

12 ஜோதிர் லிங்கம்
Courtesy: wikipedia

PS: Visited One in Tamil Nadu, One is AP and Three in Maharastra. Planned to complete remaining in next 3-5 years. Visit and get almighty blessings and Peace.