INDIA, February 12, 2018 (Travel Blog from India by Anuradha Goyal): Sirsi is the heart of Uttara Kannada nested in the lush green Western Ghats. Almost every road from here takes you to a scenic place. This time while visiting Sirsi, we decided to take a few small trips from around the town. Sahasralinga is an ancient site on the riverbed of river Shalmala. About 10.5 miles from Sirsi, near the village of Sonda, quietly flows the Shalmala. Surrounded by forests, a part of this river hides an incredible heritage and a piece of history. The bed of the Shalmala River has huge rocks – some of them can be called boulders. In dark gray color, they seem to be hard granite stones. The big and small stones have Shivalingas carved on them. Legend is that there are more than a thousand Linga hence the name Sahasralinga. Most of them even have the Nandi – Shiva’s vehicle carved on them. Some stones here have more than one Shivalinga.

The legend of Sahasralinga says the king of Sonda or Swadi Akasappa Nayaka has no children. He was advised by a priest to make 1008 Shivalingas to be blessed with children. So, the king had every stone at the bed of the Shalmala River converted into a Shivalinga. The story goes that he then had children. So, these are votive [something offered in fulfillment of a vow] Linga as in something made to get something in return. In Hindi, we would call them Ichhapoorti Shivalingas or wish-fulfilling Shivalingas.

Must see photos at source.
https://www.inditales.com/sahasralinga-sirsi-thousand-shivalingas/