Once Ravan and Mandodari on there journey had a stay near Alwar.
Mandodari invited Ravan to have some food which was denied by him as he had avow to have food only after prabhu darshan but in this forest, he was unable to find any pratimaji.
By looking at this Mandodari went to a nearby lake and made a Pratima from Valu(Balu) and took it to Ravan, chanting Navkar mantra.
After performing all the rituals, they had their food.
By their devotion and faith, the Adhishthayak dev converted the Pratima into hardrock type known as Vajra.
This Pratima is known as Ravan Parshwanath.
The Prachin Jinalay existed till 15th Century after which Shresthi Hiranand built anew Jinalay in Alwar in VK 1654 and Pratishtha was done over there.