Siddhars are Realized Souls.
Though there reported to be thousands of them, Eighteen of them are regarded as Primary Siddhas.
The first Siddha is Lord Shiva, whose disciple was Nandeswara and his disciple was Sage Agastya.
I have wriiten on the Siddhas in detail and on the abodes of Siddhas,especially of Chaturagiri,Tamil Nadu.
Chaturagiri and Kolli hills are said to be inhabited by the Siddhas and are reported to be visible at nights sometimes and on specifc days like the Full Moon.
They perform poojas and there are authentic accounts of poojas being performed by them by people noticing the flowers being found at the feet of the Idol in a temple locked at night.
People have reported hearing the sound of bells in the dead of the night inside the locked Sanctum Sanctorum.
Most of them have been verified and validated.
Siddhas transcend Space Time constraints,both being an instrument and impediment of the Mind.
Please read my articles on Perception, Time non linear and Cyclic.
In our parlance they live eternally.
They can materialize and dematerialize.
I have written an article how a man dematerialized whose hands I was holding.
The Siddhas follow a specific system mainly the Vaasi Yoga.
Kindly read my article Vaasi Yoga is Shiva.
They also have other technics which are trasnsmitted to the spiritually deserving.
In return they ask for nothing.
If one’s desire to meet a Siddha is strong he shall reach the seeker.
The works of the Siddhas is in Tamil language.
I shall provide a complete list shortly.
The language is simple but the inner meaning needs hardwork.
They are also physicians and surgeons.
Trilinga Swamigal who lived in North India was also present in south India as Kuzhandai Swamigal with whom my father and aunt were closely in touch.
Kuzhandai Swamigal was in south India,spent most of his time in Madurai.
I have recorded some facts known to my family.
They lived in their mortal frames during late eighteenth and early nineteenth century.
Even today there are reports of these Siddhas performing poojas in Chaturagiri and Kolli Malai.
There are caves in these regions and Siddhas perform poojas, not only for Gods,especially Shiva but perform poojas for the other Siddhas.
One such pooja was conducted by a Siddha to Siddha Korakkar.
In the following video by Zee Tamil as a part of Investigative Journalism a man, obviously a Siddha performing pooja to Siddha Korakkar.
He sits and meditates.
Garland moves on its own and adorns Korakka.
Flowers fall at his feet while the Siddha performing the pooja is away from the Flowers.
The cave resonates with OM.
The camphor lights on its own.
And once the Siddha completes his meditation,and raises both his hands in prayer to Korakkar, the Siddha who has been meditating and raising hands dematerialized.
This has been captured in Video by Zee Tamil in their serial Naminaal Nambungal, Belive it It or Not.
Watch the Video.